diff --git a/avogadro/qtgui/molecule.cpp b/avogadro/qtgui/molecule.cpp
index b6a9563654..41c6bee3a6 100644
--- a/avogadro/qtgui/molecule.cpp
+++ b/avogadro/qtgui/molecule.cpp
@@ -13,15 +13,15 @@ namespace Avogadro::QtGui {
 using std::swap;
 
 Molecule::Molecule(QObject* parent_)
-  : QObject(parent_),
-    m_undoMolecule(new RWMolecule(*this, this)), Core::Molecule()
+  : QObject(parent_), Core::Molecule(),
+    m_undoMolecule(new RWMolecule(*this, this)), constraints()
 {
   m_undoMolecule->setInteractive(true);
 }
 
 Molecule::Molecule(const Molecule& other)
   : QObject(), Core::Molecule(other),
-    m_undoMolecule(new RWMolecule(*this, this))
+    m_undoMolecule(new RWMolecule(*this, this)), constraints()
 {
   m_undoMolecule->setInteractive(true);
   // Now assign the unique ids
@@ -33,7 +33,7 @@ Molecule::Molecule(const Molecule& other)
 }
 
 Molecule::Molecule(const Core::Molecule& other)
-  : QObject(), Core::Molecule(other)
+  : QObject(), Core::Molecule(other), constraints()
 {
   // Now assign the unique ids
   for (Index i = 0; i < atomCount(); i++)
@@ -204,8 +204,8 @@ void Molecule::swapAtom(Index a, Index b)
   Core::Molecule::swapAtom(a, b);
 }
 
-Molecule::BondType Molecule::addBond(Index a, Index b,
-                                     unsigned char order, Index uniqueId)
+Molecule::BondType Molecule::addBond(Index a, Index b, unsigned char order,
+                                     Index uniqueId)
 {
   if (uniqueId >= static_cast<Index>(m_bondUniqueIds.size()) ||
       m_bondUniqueIds[uniqueId] != MaxIndex) {
diff --git a/avogadro/qtgui/molecule.h b/avogadro/qtgui/molecule.h
index 9eb86ff981..d0e5fb89e5 100644
--- a/avogadro/qtgui/molecule.h
+++ b/avogadro/qtgui/molecule.h
@@ -18,6 +18,11 @@
 #include <list>
 
 namespace Avogadro {
+
+namespace QtPlugins {
+    class ConstraintsModel;
+}
+
 namespace QtGui {
 
 class Mesh;
@@ -33,6 +38,9 @@ class AVOGADROQTGUI_EXPORT Molecule : public QObject, public Core::Molecule
   Q_OBJECT
 
 public:
+
+  QtPlugins::ConstraintsModel* constraints;
+
   /** Typedef for Atom class. */
   typedef Core::Molecule::AtomType AtomType;
 
diff --git a/avogadro/qtplugins/CMakeLists.txt b/avogadro/qtplugins/CMakeLists.txt
index f36c852048..fda86967c4 100644
--- a/avogadro/qtplugins/CMakeLists.txt
+++ b/avogadro/qtplugins/CMakeLists.txt
@@ -186,6 +186,9 @@ if(BUILD_GPL_PLUGINS)
   add_subdirectory(qtaim)
 endif()
 
+#kantundpeterpan
+add_subdirectory(constraints)
+
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${original_library_output_dir}")
 
 # Add all of the static plugins to the initialization file.
diff --git a/avogadro/qtplugins/constraints/CMakeLists.txt b/avogadro/qtplugins/constraints/CMakeLists.txt
new file mode 100644
index 0000000000..4c86e2c525
--- /dev/null
+++ b/avogadro/qtplugins/constraints/CMakeLists.txt
@@ -0,0 +1,23 @@
+include_directories("${AvogadroLibs_SOURCE_DIR}/thirdparty")
+
+set(constraints
+  constraintsextension.cpp
+  constraintsdialog.cpp
+  constraintsmodel.cpp
+  constraint.cpp
+)
+
+set(constraints_uis
+  constraintsdialog.ui
+)
+
+avogadro_plugin(ConstraintsExtension
+  "Constraints extension"
+  ExtensionPlugin
+  constraintsextension.h
+  ConstraintsExtension
+  "${constraints}"
+  "${constraints_uis}"
+)
+
+target_link_libraries(ConstraintsExtension)
diff --git a/avogadro/qtplugins/constraints/constraint.cpp b/avogadro/qtplugins/constraints/constraint.cpp
new file mode 100644
index 0000000000..3676361004
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraint.cpp
@@ -0,0 +1,176 @@
+#include "constraint.h"
+
+namespace Avogadro {
+  namespace QtPlugins {
+
+    Constraint::Constraint(int type,
+                           int a,
+                           int b,
+                           int c,
+                           int d,
+                           double value,
+                           ConstraintsModel* model)
+    {
+      c_model = model;
+      ConstraintType = type;
+
+      //adjusting for 0 indexing
+      a = a-1;
+      b = b-1;
+      c = c-1;
+      d = d-1;
+
+      // store unique AtomIds
+
+      switch (ConstraintType)
+        {
+        case 0:
+        case 1:
+        case 2:
+        case 3:
+        case 4:
+          // AtomA
+          Atoms << c_model->c_molecule->atomUniqueId(a);
+          break;
+
+        case 5:
+          //AtomA
+          Atoms << c_model->c_molecule->atomUniqueId(a);
+          //AtomB
+          Atoms << c_model->c_molecule->atomUniqueId(b);
+          break;
+
+        case 6:
+          //AtomA
+          Atoms << c_model->c_molecule->atomUniqueId(a);
+          //AtomB
+          Atoms << c_model->c_molecule->atomUniqueId(b);
+          //AtomC
+          Atoms << c_model->c_molecule->atomUniqueId(c);
+          break;
+
+        case 7:
+          //AtomA
+          Atoms << c_model->c_molecule->atomUniqueId(a);
+          //AtomB
+          Atoms << c_model->c_molecule->atomUniqueId(b);
+          //AtomC
+          Atoms << c_model->c_molecule->atomUniqueId(c);
+          //AtomD
+          Atoms << c_model->c_molecule->atomUniqueId(d);
+        }
+
+      ConstraintValue = value;
+
+    }
+
+    Constraint::~Constraint(){}
+
+    void Constraint::SetConstraintType(int type)
+    {
+      ConstraintType = type;
+    }
+
+    void Constraint::SetValue(double Value)
+    {
+      ConstraintValue = Value;
+    }
+
+    int Constraint::GetConstraintType() const
+    {
+      return ConstraintType;
+    }
+
+    double Constraint::GetConstraintValue() const
+    {
+      return ConstraintValue;
+    }
+
+    const Index Constraint::GetConstraintAtomA() const
+    {
+      if (Atoms.size() >= 1) //returned for all constraint types
+        {
+          return c_model->c_molecule->atomByUniqueId(Atoms[0]).index()+1;
+        }
+      else
+        {
+          return 0;
+        }
+    }
+
+    const Index Constraint::GetConstraintAtomB() const
+    {
+      if (Atoms.size() >= 2) //distance, angle and torsion constraints
+        {
+          return c_model->c_molecule->atomByUniqueId(Atoms[1]).index()+1;
+        }
+      else
+        {
+          return 0;
+        }
+    }
+
+    const Index Constraint::GetConstraintAtomC() const
+    {
+      if (Atoms.size() >= 3) //angle and torsion constraints
+        {
+          return c_model->c_molecule->atomByUniqueId(Atoms[2]).index()+1;
+        }
+      else
+        {
+          return 0;
+        }
+    }
+
+    const Index Constraint::GetConstraintAtomD() const
+    {
+      if (Atoms.size() >= 4) //torsion constraints only
+        {
+          return c_model->c_molecule->atomByUniqueId(Atoms[3]).index()+1;
+        }
+      else
+        {
+          return 0;
+        }
+    }
+
+    QJsonObject Constraint::toJson()
+    {
+      QJsonObject ConstraintJ;
+      ConstraintJ["type"] = GetConstraintType();
+      ConstraintJ["value"] = GetConstraintValue();
+
+      QJsonArray ConstraintAtoms;
+
+      switch (GetConstraintType())
+        {
+        case 0:
+        case 1:
+        case 2:
+        case 3:
+        case 4:
+          ConstraintAtoms << static_cast<int>(GetConstraintAtomA());
+          break;
+        case 5:
+          ConstraintAtoms << static_cast<int>(GetConstraintAtomA())
+                          << static_cast<int>(GetConstraintAtomB());
+          break;
+        case 6:
+          ConstraintAtoms << static_cast<int>(GetConstraintAtomA())
+                          << static_cast<int>(GetConstraintAtomB())
+                          << static_cast<int>(GetConstraintAtomC());
+          break;
+        case 7:
+          ConstraintAtoms << static_cast<int>(GetConstraintAtomA())
+                          << static_cast<int>(GetConstraintAtomB())
+                          << static_cast<int>(GetConstraintAtomC())
+                          << static_cast<int>(GetConstraintAtomD());
+          break;
+        }
+
+      ConstraintJ.insert("atoms", ConstraintAtoms);
+
+      return ConstraintJ;
+    }
+  } //namespace QtPlugins
+}  //namespace Avogadro
diff --git a/avogadro/qtplugins/constraints/constraint.h b/avogadro/qtplugins/constraints/constraint.h
new file mode 100644
index 0000000000..966058b0ad
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraint.h
@@ -0,0 +1,70 @@
+#include <QtCore>
+#include <QJsonObject>
+#include <QList>
+
+#include <avogadro/qtgui/molecule.h>
+#include "constraintsmodel.h"
+
+#ifndef CONSTRAINT_H
+#define CONSTRAINT_H
+
+namespace Avogadro {
+  namespace Core{
+    class Atom;
+  }
+  namespace QtPlugins {
+    class Constraint
+    {
+    public:
+      /*
+        Implementation of simple class for the represenation of constraints.
+
+        The ConstraintType has the following mapping (reflected in the ConstraintDialog combobox):
+
+        0: Ignore Atom
+        1: Fix Atom
+        2: Fix Atom X
+        3: Fix Atom Y
+        4: Fix Atom Z
+        5: Distance
+        6: Angle
+        7: Torsion
+
+        This implementation makes use of the UniqueID that is assigned to each Atom upon creation,
+        which can be used to unambigously retrieve the current index of the Atom in molecule.
+
+        This constraint representation has to be translated into package specific instructions when
+        passing it to whatever Optimizing/MD/QM code.
+
+       */
+      explicit Constraint(int ConstraintType,
+                          int AtomIdA,
+                          int AtomIdB,
+                          int AtomIdC,
+                          int AtomIdD,
+                          double ConstraintValue,
+                          ConstraintsModel* model);
+      ~Constraint();
+
+      void SetConstraintType(int ConstraintType);
+      void SetValue(double Value);
+
+      int  GetConstraintType() const;
+      double GetConstraintValue() const;
+
+      const Index GetConstraintAtomA() const;
+      const Index GetConstraintAtomB() const;
+      const Index GetConstraintAtomC() const;
+      const Index GetConstraintAtomD() const;
+
+      QJsonObject toJson();
+
+      int ConstraintType;
+      double ConstraintValue;
+
+      QList<Index> Atoms;
+      ConstraintsModel* c_model = nullptr;
+    };    
+  }
+}
+#endif
diff --git a/avogadro/qtplugins/constraints/constraintsdialog.cpp b/avogadro/qtplugins/constraints/constraintsdialog.cpp
new file mode 100644
index 0000000000..442de90781
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraintsdialog.cpp
@@ -0,0 +1,130 @@
+#include "constraintsdialog.h"
+#include "ui_constraintsdialog.h"
+
+#include <QPushButton>
+#include <QButtonGroup>
+#include <QDebug>
+#include <QTextStream>
+
+using Avogadro::QtGui::Molecule;
+
+//#include <QFileDialog>
+//#include <QFile>
+//#include <QString>
+//#include <QMessageBox>
+//#include <string>
+
+namespace Avogadro {
+  namespace QtPlugins {
+    ConstraintsDialog::ConstraintsDialog(ConstraintsExtension* plugin,
+                                         QWidget* parent_,
+                                         Qt::WindowFlags f)
+      : QDialog(parent_,f)
+      , m_plugin(plugin)
+      , ui(new Ui::ConstraintsDialog)
+    {
+      ui->setupUi(this);
+      connect( ui->ConstraintsOK, SIGNAL( clicked() ), this, SLOT( acceptConstraints() ));
+      connect( ui->ConstraintsAdd, SIGNAL( clicked() ), this, SLOT( addConstraint() ));
+      connect( ui->ConstraintsDelete, SIGNAL( clicked() ), this, SLOT( deleteConstraint() ));
+      connect( ui->ConstraintsDeleteAll, SIGNAL( clicked() ), this, SLOT( deleteAllConstraints() ));
+      //      connect( ui->HighlightButton, SIGNAL( clicked() ), this, SLOT( highlightSelected()));
+      connect( ui->checkHighlight, SIGNAL( stateChanged(int)), this, SLOT( connectHighlight(int)));
+    }
+
+    ConstraintsDialog::~ConstraintsDialog()
+    {
+      delete ui;
+    }
+
+    void ConstraintsDialog::connectHighlight(int state)
+    {
+      if (state)
+        {
+          connect(ui->ConstraintsTableView->selectionModel(),
+                  SIGNAL( selectionChanged(QItemSelection, QItemSelection)),
+                  this, SLOT (highlightSelected()));
+        }
+      else
+        {
+          disconnect(ui->ConstraintsTableView->selectionModel(),
+                     SIGNAL( selectionChanged(QItemSelection, QItemSelection)),
+                     this, SLOT (highlightSelected()));
+        }
+    }
+
+    void ConstraintsDialog::highlightSelected()
+    {// check if highlighting requestd
+      if (ui->checkHighlight->checkState())
+        {//clear all previous selections
+          for (int i = 0; i < m_plugin->m_molecule->atomCount(); ++i)
+            {
+              m_plugin->m_molecule->atom(i).setSelected(false);
+            }
+          if (m_plugin->m_molecule->constraints->ConstraintsList.size()>0)
+            {
+              // get currently selected constraint
+              QModelIndex idx = ui->ConstraintsTableView->selectionModel()->currentIndex();
+              // extract selected constraint from ConstraintModel
+              QtPlugins::Constraint* c = &m_plugin->m_molecule->constraints->ConstraintsList[idx.row()];
+              // iterate over involved uniqueAtomIDs
+              for (int i = 0; i < c->Atoms.size(); i++)
+                {
+                  // get atom by uniqueID and set selected
+                  m_plugin->m_molecule->atomByUniqueId(c->Atoms[i]).setSelected(true);
+                  qDebug() << "Set selected";
+                }
+              //emit molecule changes
+              m_plugin->m_molecule->emitChanged(Molecule::Atoms);
+            }
+        }
+    }
+
+    void ConstraintsDialog::setModel()
+    {
+      ui->ConstraintsTableView->setModel(m_plugin->m_molecule->constraints);
+      connectHighlight(ui->checkHighlight->checkState());
+      connect( m_plugin->m_molecule, SIGNAL( changed(unsigned int)),
+               m_plugin->m_molecule->constraints, SLOT (emitDataChanged()));
+    }
+
+    void ConstraintsDialog::acceptConstraints()
+    {
+      hide();
+    }
+
+    void ConstraintsDialog::deleteConstraint()
+    {
+      m_plugin->
+        m_molecule->
+        constraints->
+        deleteConstraint(ui->ConstraintsTableView->currentIndex().row());
+    }
+
+    void ConstraintsDialog::addConstraint()
+    {
+      //Parsing user inptu
+      int type = ui->comboType->currentIndex();
+      double value = ui->editValue->value();
+      int AtomIdA = ui->editA->value();
+      int AtomIdB = ui->editB->value();
+      int AtomIdC = ui->editC->value();
+      int AtomIdD = ui->editD->value();
+
+      //adding the constraint to the molecule's CosntraintsModel
+      m_plugin->m_molecule->constraints->addConstraint(type,
+                                                       AtomIdA,
+                                                       AtomIdB,
+                                                       AtomIdC,
+                                                       AtomIdD,
+                                                       value);
+    }
+
+    void ConstraintsDialog::deleteAllConstraints()
+    {
+      m_plugin->m_molecule->constraints->clear();
+      // this->update();
+    }
+
+  }
+}
diff --git a/avogadro/qtplugins/constraints/constraintsdialog.h b/avogadro/qtplugins/constraints/constraintsdialog.h
new file mode 100644
index 0000000000..560663bfae
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraintsdialog.h
@@ -0,0 +1,43 @@
+#ifndef AVOGADRO_QTPLUGINS_CONSTRAINTSDIALOG_H
+#define AVOGADRO_QTPLUGINS_CONSTRAINTSDIALOG_H
+#include "constraintsextension.h"
+#include "constraintsmodel.h"
+#include <QDialog>
+#include <QButtonGroup>
+#include <QModelIndex>
+#include <QTableView>
+#include <QString>
+#include <string>
+
+namespace Avogadro {
+  namespace QtPlugins {
+    namespace Ui {
+      class ConstraintsDialog;
+    }
+    class ConstraintsDialog : public QDialog
+    {
+      Q_OBJECT
+
+    public:
+      explicit ConstraintsDialog(ConstraintsExtension* plugin ,
+                                 QWidget* parent_=0,
+                                 Qt::WindowFlags f = 0);
+      ~ConstraintsDialog() override;
+      void setModel();
+      
+    public slots:
+      void acceptConstraints();
+      void addConstraint();
+      void deleteConstraint();
+      void deleteAllConstraints();
+      void highlightSelected();
+      void connectHighlight(int state);
+
+    private:
+      Ui::ConstraintsDialog* ui;
+      ConstraintsExtension* m_plugin;
+      
+    };
+  }
+}
+#endif //AVOGADRO_QTPLUGINS_CONSTRAINTSDIALOG_H
diff --git a/avogadro/qtplugins/constraints/constraintsdialog.ui b/avogadro/qtplugins/constraints/constraintsdialog.ui
new file mode 100644
index 0000000000..ee526432cb
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraintsdialog.ui
@@ -0,0 +1,220 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>Avogadro::QtPlugins::ConstraintsDialog</class>
+ <widget class="QDialog" name="Avogadro::QtPlugins::ConstraintsDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>798</width>
+    <height>357</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Constraints</string>
+  </property>
+  <layout class="QVBoxLayout">
+   <item>
+    <widget class="QTableView" name="ConstraintsTableView">
+     <property name="selectionBehavior">
+      <enum>QAbstractItemView::SelectRows</enum>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox">
+     <property name="title">
+      <string>Add Constraints</string>
+     </property>
+     <layout class="QHBoxLayout">
+      <item>
+       <layout class="QHBoxLayout">
+        <item>
+         <widget class="QLabel" name="label">
+          <property name="maximumSize">
+           <size>
+            <width>40</width>
+            <height>16777215</height>
+           </size>
+          </property>
+          <property name="text">
+           <string>Type</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QComboBox" name="comboType">
+          <item>
+           <property name="text">
+            <string>Ignore Atom</string>
+           </property>
+          </item>
+          <item>
+           <property name="text">
+            <string>Fix Atom</string>
+           </property>
+          </item>
+          <item>
+           <property name="text">
+            <string>Fix Atom X</string>
+           </property>
+          </item>
+          <item>
+           <property name="text">
+            <string>Fix Atom Y</string>
+           </property>
+          </item>
+          <item>
+           <property name="text">
+            <string>Fix Atom Z</string>
+           </property>
+          </item>
+          <item>
+           <property name="text">
+            <string>Distance</string>
+           </property>
+          </item>
+          <item>
+           <property name="text">
+            <string>Angle</string>
+           </property>
+          </item>
+          <item>
+           <property name="text">
+            <string>Torsion angle</string>
+           </property>
+          </item>
+         </widget>
+        </item>
+        <item>
+         <widget class="QLabel" name="label_2">
+          <property name="text">
+           <string>Constraint Value</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QDoubleSpinBox" name="editValue"/>
+        </item>
+        <item>
+         <widget class="QLabel" name="label_3">
+          <property name="text">
+           <string>Atom Indices</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editA"/>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editB"/>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editC"/>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editD"/>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsAdd">
+          <property name="text">
+           <string>Add</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox_2">
+     <property name="title">
+      <string>Options</string>
+     </property>
+     <layout class="QHBoxLayout">
+      <item>
+       <layout class="QHBoxLayout">
+        <item>
+         <widget class="QPushButton" name="ConstraintsSave">
+          <property name="enabled">
+           <bool>false</bool>
+          </property>
+          <property name="text">
+           <string>Save</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsLoad">
+          <property name="enabled">
+           <bool>false</bool>
+          </property>
+          <property name="text">
+           <string>Load</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <spacer>
+          <property name="orientation">
+           <enum>Qt::Horizontal</enum>
+          </property>
+          <property name="sizeHint" stdset="0">
+           <size>
+            <width>40</width>
+            <height>20</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
+        <item>
+         <widget class="QCheckBox" name="checkHighlight">
+          <property name="text">
+           <string>Highlight selected Constraint</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsDelete">
+          <property name="sizePolicy">
+           <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
+            <horstretch>0</horstretch>
+            <verstretch>0</verstretch>
+           </sizepolicy>
+          </property>
+          <property name="minimumSize">
+           <size>
+            <width>100</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="text">
+           <string>Delete Selected</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsDeleteAll">
+          <property name="text">
+           <string>Delete All</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsOK">
+          <property name="text">
+           <string>OK</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/avogadro/qtplugins/constraints/constraintsdialog_small.ui b/avogadro/qtplugins/constraints/constraintsdialog_small.ui
new file mode 100644
index 0000000000..cefe05bdb8
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraintsdialog_small.ui
@@ -0,0 +1,205 @@
+<ui version="4.0" >
+ <class>Avogadro::QtPlugins::ConstraintsDialog</class>
+ <widget class="QDialog" name="Avogadro::QtPlugins::ConstraintsDialog" >
+  <property name="geometry" >
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>750</width>
+    <height>357</height>
+   </rect>
+  </property>
+  <property name="windowTitle" >
+   <string>Constraints</string>
+  </property>
+  <layout class="QVBoxLayout" >
+   <item>
+    <widget class="QTableView" name="ConstraintsTableView" >
+     <property name="selectionBehavior" >
+      <enum>QAbstractItemView::SelectRows</enum>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox" >
+     <property name="title" >
+      <string>Add Constraints</string>
+     </property>
+     <layout class="QHBoxLayout" >
+      <item>
+       <layout class="QHBoxLayout" >
+        <item>
+         <widget class="QLabel" name="label" >
+          <property name="maximumSize" >
+           <size>
+            <width>40</width>
+            <height>16777215</height>
+           </size>
+          </property>
+          <property name="text" >
+           <string>Type</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QComboBox" name="comboType" >
+          <item>
+           <property name="text" >
+            <string>Fix Atom</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Distance</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Angle</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Torsion angle</string>
+           </property>
+          </item>
+         </widget>
+        </item>
+        <item>
+         <widget class="QLabel" name="label_2" >
+          <property name="text" >
+           <string>Constraint Value</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QDoubleSpinBox" name="editValue" />
+        </item>
+        <item>
+         <widget class="QLabel" name="label_3" >
+          <property name="text" >
+           <string>Atom Indices</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editA" />
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editB" />
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editC" />
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editD" />
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsAdd" >
+          <property name="text" >
+           <string>Add</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox_2" >
+     <property name="title" >
+      <string>Options</string>
+     </property>
+     <layout class="QHBoxLayout" >
+      <item>
+       <layout class="QHBoxLayout" >
+        <item>
+         <widget class="QPushButton" name="ConstraintsSave" >
+          <property name="enabled" >
+           <bool>false</bool>
+          </property>
+          <property name="text" >
+           <string>Save</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsLoad" >
+          <property name="enabled" >
+           <bool>false</bool>
+          </property>
+          <property name="text" >
+           <string>Load</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <spacer>
+          <property name="orientation" >
+           <enum>Qt::Horizontal</enum>
+          </property>
+          <property name="sizeHint" >
+           <size>
+            <width>40</width>
+            <height>20</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsDelete" >
+          <property name="sizePolicy" >
+           <sizepolicy vsizetype="Fixed" hsizetype="Minimum" >
+            <horstretch>0</horstretch>
+            <verstretch>0</verstretch>
+           </sizepolicy>
+          </property>
+          <property name="minimumSize" >
+           <size>
+            <width>100</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="text" >
+           <string>Delete Selected</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsDeleteAll" >
+          <property name="text" >
+           <string>Delete All</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <spacer>
+          <property name="orientation" >
+           <enum>Qt::Horizontal</enum>
+          </property>
+          <property name="sizeHint" >
+           <size>
+            <width>40</width>
+            <height>20</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsOK" >
+          <property name="text" >
+           <string>OK</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/avogadro/qtplugins/constraints/constraintsextension.cpp b/avogadro/qtplugins/constraints/constraintsextension.cpp
new file mode 100644
index 0000000000..dac9ff068f
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraintsextension.cpp
@@ -0,0 +1,65 @@
+#include "constraintsextension.h"
+#include "constraintsdialog.h"
+#include "constraintsmodel.h"
+
+#include <QAction>
+
+//#include <QTextStream>
+//#include <QString>
+
+#include <string>
+#include <iostream>
+
+namespace Avogadro {
+  namespace QtPlugins {
+    ConstraintsExtension::ConstraintsExtension(QObject* p) : ExtensionPlugin(p)
+    {
+      QAction* action = new QAction(this);
+      action->setEnabled(true);
+      action->setText(tr("Constraints"));
+      connect(action, SIGNAL(triggered()), SLOT(onDialog()));
+      m_actions.push_back(action);
+
+      dialog = new ConstraintsDialog(this,
+                                     qobject_cast<QWidget*>(parent()));
+
+    }
+
+    ConstraintsExtension::~ConstraintsExtension(){}
+
+    QList<QAction*> ConstraintsExtension::actions() const{
+      return m_actions;
+      }
+
+    QStringList ConstraintsExtension::menuPath(QAction*) const{
+      return QStringList() << tr("&Extensions");
+    }
+
+    
+    void ConstraintsExtension::onDialog()
+    {
+      dialog->show();
+      
+    }
+    
+
+    void ConstraintsExtension::setMolecule(QtGui::Molecule* mol)
+    {
+      if (mol != m_molecule)
+        {
+          m_molecule = mol;
+          //          dialog->connectHighlight(0);
+        }
+
+      if (!m_molecule->constraints)
+        {
+          m_molecule->constraints = new ConstraintsModel(m_molecule);
+        }
+      dialog->setModel();
+    }
+
+    bool ConstraintsExtension::readMolecule(QtGui::Molecule& mol){
+      return true;
+    }
+  }
+}
diff --git a/avogadro/qtplugins/constraints/constraintsextension.h b/avogadro/qtplugins/constraints/constraintsextension.h
new file mode 100644
index 0000000000..98c89c9343
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraintsextension.h
@@ -0,0 +1,49 @@
+#ifndef AVOGADRO_QTPLUGINS_CONSTRAINTS_H
+#define AVOGADRO_QTPLUGINS_CONSTRAINTS_H
+
+#include <avogadro/qtgui/molecule.h>
+#include <avogadro/qtgui/extensionplugin.h>
+#include <QtCore/QMap>
+
+class QAction;
+
+namespace Avogadro {
+  namespace QtPlugins {
+    class ConstraintsDialog;
+
+    class ConstraintsExtension : public QtGui::ExtensionPlugin
+    {
+      Q_OBJECT
+
+    public:
+      explicit ConstraintsExtension(QObject* parent=0);
+      ~ConstraintsExtension() override;
+
+      QString name() const override { return tr("Constraints");}
+
+      QString description() const override {
+        return tr("Set Constraints for MM and QM optimizations");
+      }
+
+      QList<QAction*> actions() const override;
+
+      QStringList menuPath(QAction*) const override;
+
+      void setMolecule(QtGui::Molecule* mol) override;
+
+      bool readMolecule(QtGui::Molecule& mol) override;
+
+    private slots:
+      void onDialog();
+
+    private:
+      QList<QAction*> m_actions;
+      QtGui::Molecule* m_molecule = nullptr;
+      ConstraintsDialog* dialog = nullptr;
+
+      friend class ConstraintsDialog;
+    };
+  }
+}
+
+#endif // AVOGADRO_QTPLUGINS_CONSTRAINTS_H
diff --git a/avogadro/qtplugins/constraints/constraintsmodel.cpp b/avogadro/qtplugins/constraints/constraintsmodel.cpp
new file mode 100644
index 0000000000..f1a7fe78e3
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraintsmodel.cpp
@@ -0,0 +1,187 @@
+#include "constraintsmodel.h"
+#include <QtCore/QMutexLocker>
+#include <QtCore/QDebug>
+#include <QString>
+
+
+using namespace std;
+
+namespace Avogadro
+{
+  namespace QtPlugins{
+
+    void ConstraintsModel::emitDataChanged()
+    {
+      emit dataChanged(QModelIndex(), QModelIndex());
+    }
+    
+    int ConstraintsModel::rowCount(const QModelIndex &) const
+    {
+      return ConstraintsList.size();
+    }
+
+    int ConstraintsModel::columnCount(const QModelIndex &) const
+    {
+      return 6;
+    }
+
+    QVariant ConstraintsModel::data(const QModelIndex &index, int role) const
+    {
+      if (!index.isValid())
+        return QVariant();
+
+      if (index.row() >= ConstraintsList.size())
+        return QVariant();
+
+      if (role == Qt::DisplayRole)
+        switch (index.column()) {
+        case 0:
+          if (ConstraintsList[index.row()].GetConstraintType() == 0)
+            return QString("Ignore Atom");
+          else if (ConstraintsList[index.row()].GetConstraintType() == 1)
+            return QString("Fix Atom");
+          else if (ConstraintsList[index.row()].GetConstraintType() == 2)
+            return QString("Fix Atom X");
+          else if (ConstraintsList[index.row()].GetConstraintType() == 3)
+            return QString("Fix Atom Y");
+          else if (ConstraintsList[index.row()].GetConstraintType() == 4)
+            return QString("Fix Atom Z");
+          else if (ConstraintsList[index.row()].GetConstraintType() == 5)
+            return QString("Distance");
+          else if (ConstraintsList[index.row()].GetConstraintType() == 6)
+            return QString("Angle");
+          else if (ConstraintsList[index.row()].GetConstraintType() == 7)
+            return QString("Torsion angle");
+          break;
+        case 1:
+          return ConstraintsList[index.row()].GetConstraintValue();
+          break;
+        case 2:
+          if (ConstraintsList[index.row()].GetConstraintAtomA())
+            {
+              QVariant v;
+              v.setValue(static_cast<int>(ConstraintsList[index.row()].GetConstraintAtomA()));
+              return v;
+            }
+          else
+            {
+              return "NA";
+            }
+          break;
+        case 3:
+          if (ConstraintsList[index.row()].GetConstraintAtomB())
+            {
+              QVariant v;
+              v.setValue(static_cast<int>(ConstraintsList[index.row()].GetConstraintAtomB()));
+              return v;
+            }
+          else
+            {
+              return "NA";
+            }
+          break;
+        case 4:
+          if (ConstraintsList[index.row()].GetConstraintAtomC())
+            {
+              QVariant v;
+              v.setValue(static_cast<int>(ConstraintsList[index.row()].GetConstraintAtomC()));
+              return v;
+            }
+          else
+            {
+              return "NA";
+                }
+          break;
+        case 5:
+          if (ConstraintsList[index.row()].GetConstraintAtomD())
+            {
+              QVariant v;
+              v.setValue(static_cast<int>(ConstraintsList[index.row()].GetConstraintAtomD()));
+              return v;
+            }
+          else
+            {
+              return "NA";
+                }
+          break;
+        }
+
+      return QVariant();
+    }
+  
+    QVariant ConstraintsModel::headerData(int section, Qt::Orientation orientation, int role) const
+    {
+      if (role != Qt::DisplayRole)
+        return QVariant();
+
+      if (orientation == Qt::Horizontal) {
+        switch (section) {
+        case 0:
+          return QString("Type");
+          break;
+        case 1:
+          return QString("Value");
+          break;
+        case 2:
+          return QString("Atom idx 1");
+          break;
+        case 3:
+          return QString("Atom idx 2");
+          break;
+        case 4:
+          return QString("Atom idx 3");
+          break;
+        case 5:
+          return QString("Atom idx 4");
+          break;
+        }
+      }
+    
+      return QString("Constraint %1").arg(section + 1);
+    }
+
+    void ConstraintsModel::addConstraint(int type, int a, int b, int c, int d, double value)
+    {
+      beginInsertRows(QModelIndex(), ConstraintsList.size(), ConstraintsList.size());
+      ConstraintsList << Constraint(type, a, b, c, d, value, this);
+      endInsertRows();
+    }
+ 
+    void ConstraintsModel::clear()
+    {
+      qDebug() << "ConstraintsModel::clear()" << endl;
+      if (ConstraintsList.size()) {
+        beginRemoveRows(QModelIndex(), 0, ConstraintsList.size() - 1); 
+        ConstraintsList.clear();
+        endRemoveRows();
+      }
+    }
+  
+    void ConstraintsModel::deleteConstraint(int index)
+    { 
+      qDebug() << "ConstraintsModel::deleteConstraint(" << index << ")" << endl;
+      if (ConstraintsList.size() && (index >= 0)) {
+        beginRemoveRows(QModelIndex(), index, index); 
+        ConstraintsList.removeAt(index);
+        endRemoveRows();
+      }
+    }
+
+    QJsonObject ConstraintsModel::toJson()
+    {
+      QJsonObject ConstraintsMJ;
+      ConstraintsMJ["total"] = ConstraintsList.size();
+
+      if(ConstraintsList.size())
+        {
+        for(int i = 0; i < ConstraintsList.size(); i++)
+          {
+            ConstraintsMJ.insert(QString::number(i), ConstraintsList[i].toJson());
+          }
+        }
+
+      return ConstraintsMJ;
+    }
+  }
+} // end namespace Avogadro
+
diff --git a/avogadro/qtplugins/constraints/constraintsmodel.h b/avogadro/qtplugins/constraints/constraintsmodel.h
new file mode 100644
index 0000000000..b2d12cba31
--- /dev/null
+++ b/avogadro/qtplugins/constraints/constraintsmodel.h
@@ -0,0 +1,56 @@
+#ifndef CONSTRAINTSMODEL_H
+#define CONSTRAINTSMODEL_H
+
+#include <QtCore/QObject>
+#include <QtCore/QList>
+#include <QtCore/QString>
+#include <QtCore/QAbstractTableModel>
+#include <QJsonObject>
+#include <QJsonDocument>
+
+#include <avogadro/qtgui/molecule.h>
+#include "constraint.h"
+
+
+namespace Avogadro {
+  namespace QtPlugins {
+    class ConstraintsModel : public QAbstractTableModel
+
+    {
+      Q_OBJECT
+      /* 
+    public slots:
+      void primitiveRemoved(Primitive *primitive);
+      */
+    public:
+      ConstraintsModel(QtGui::Molecule* molecule)
+        : QAbstractTableModel()
+        , c_molecule(molecule)
+      {}
+
+      int rowCount(const QModelIndex &parent = QModelIndex()) const;
+      int columnCount(const QModelIndex &parent = QModelIndex()) const;
+      QVariant data(const QModelIndex &index, int role) const;
+      QVariant headerData(int section, Qt::Orientation orientation,
+                          int role = Qt::DisplayRole) const;
+       
+      void clear();
+      void addConstraint(int type, int a, int b, int c, int d, double value);
+      void deleteConstraint(int index);
+
+      QJsonObject toJson();
+
+
+      QList<Constraint> ConstraintsList;
+
+      // pointer to the associated molecule
+      QtGui::Molecule* c_molecule = nullptr;
+
+    public slots:
+      void emitDataChanged();
+
+    }; //ConstraintsModel
+  } // QtPlugins
+} // end namespace Avogadro
+
+#endif
diff --git a/avogadro/qtplugins/constraints/orig/constraintsdialog.ui b/avogadro/qtplugins/constraints/orig/constraintsdialog.ui
new file mode 100644
index 0000000000..42a3c2186d
--- /dev/null
+++ b/avogadro/qtplugins/constraints/orig/constraintsdialog.ui
@@ -0,0 +1,225 @@
+<ui version="4.0" >
+ <class>Avogadro::QtPlugins::ConstraintsDialog</class>
+ <widget class="QDialog" name="Avogadro::QtPlugins::ConstraintsDialog" >
+  <property name="geometry" >
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>750</width>
+    <height>357</height>
+   </rect>
+  </property>
+  <property name="windowTitle" >
+   <string>Constraints</string>
+  </property>
+  <layout class="QVBoxLayout" >
+   <item>
+    <widget class="QTableView" name="ConstraintsTableView" >
+     <property name="selectionBehavior" >
+      <enum>QAbstractItemView::SelectRows</enum>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox" >
+     <property name="title" >
+      <string>Add Constraints</string>
+     </property>
+     <layout class="QHBoxLayout" >
+      <item>
+       <layout class="QHBoxLayout" >
+        <item>
+         <widget class="QLabel" name="label" >
+          <property name="maximumSize" >
+           <size>
+            <width>40</width>
+            <height>16777215</height>
+           </size>
+          </property>
+          <property name="text" >
+           <string>Type</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QComboBox" name="comboType" >
+          <item>
+           <property name="text" >
+            <string>Ignore Atom</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Fix Atom</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Fix Atom X</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Fix Atom Y</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Fix Atom Z</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Distance</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Angle</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Torsion angle</string>
+           </property>
+          </item>
+         </widget>
+        </item>
+        <item>
+         <widget class="QLabel" name="label_2" >
+          <property name="text" >
+           <string>Constraint Value</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QDoubleSpinBox" name="editValue" />
+        </item>
+        <item>
+         <widget class="QLabel" name="label_3" >
+          <property name="text" >
+           <string>Atom Indices</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editA" />
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editB" />
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editC" />
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editD" />
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsAdd" >
+          <property name="text" >
+           <string>Add</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox_2" >
+     <property name="title" >
+      <string>Options</string>
+     </property>
+     <layout class="QHBoxLayout" >
+      <item>
+       <layout class="QHBoxLayout" >
+        <item>
+         <widget class="QPushButton" name="ConstraintsSave" >
+          <property name="enabled" >
+           <bool>false</bool>
+          </property>
+          <property name="text" >
+           <string>Save</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsLoad" >
+          <property name="enabled" >
+           <bool>false</bool>
+          </property>
+          <property name="text" >
+           <string>Load</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <spacer>
+          <property name="orientation" >
+           <enum>Qt::Horizontal</enum>
+          </property>
+          <property name="sizeHint" >
+           <size>
+            <width>40</width>
+            <height>20</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsDelete" >
+          <property name="sizePolicy" >
+           <sizepolicy vsizetype="Fixed" hsizetype="Minimum" >
+            <horstretch>0</horstretch>
+            <verstretch>0</verstretch>
+           </sizepolicy>
+          </property>
+          <property name="minimumSize" >
+           <size>
+            <width>100</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="text" >
+           <string>Delete Selected</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsDeleteAll" >
+          <property name="text" >
+           <string>Delete All</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <spacer>
+          <property name="orientation" >
+           <enum>Qt::Horizontal</enum>
+          </property>
+          <property name="sizeHint" >
+           <size>
+            <width>40</width>
+            <height>20</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsOK" >
+          <property name="text" >
+           <string>OK</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/avogadro/qtplugins/constraints/orig/constraintsdialog_orig.cpp b/avogadro/qtplugins/constraints/orig/constraintsdialog_orig.cpp
new file mode 100644
index 0000000000..7827c28b81
--- /dev/null
+++ b/avogadro/qtplugins/constraints/orig/constraintsdialog_orig.cpp
@@ -0,0 +1,27 @@
+#include "constraintsdialog.h"
+#include "ui_constraintsdialog.h"
+#include <QPushButton>
+#include <QButtonGroup>
+#include <QDebug>
+
+#include <QFileDialog>
+#include <QFile>
+
+#include <QMessageBox>
+
+namespace Avogadro {
+  namespace QtPlugins {
+    ConstraintsDialog::ConstraintsDialog(QWidget* parent_) : QDialog(parent_), ui(new Ui::ConstraintsDialog)
+    {
+      ui->setupUi(this);
+    }
+    ConstraintsDialog::~ConstraintsDialog()
+    {
+      delete ui;
+    }
+    void ConstraintsDialog::whow()
+    {
+      this->show();
+    }
+  }
+}
diff --git a/avogadro/qtplugins/constraints/orig/constraintsdialog_orig.h b/avogadro/qtplugins/constraints/orig/constraintsdialog_orig.h
new file mode 100644
index 0000000000..db4c31c1e1
--- /dev/null
+++ b/avogadro/qtplugins/constraints/orig/constraintsdialog_orig.h
@@ -0,0 +1,29 @@
+#ifndef AVOGADRO_QTPLUGINS_CONSTRAINTSDIALOG_H
+#define AVOGADRO_QTPLUGINS_CONSTRAINTSDIALOG_H
+
+#include <QDialog>
+#include <QButtonGroup>
+#include <QModelIndex>
+#include <QTableView>
+
+namespace Avogadro {
+  namespace QtPlugins {
+    namespace Ui {
+      class ConstraintsDialog;
+    }
+    class ConstraintsDialog : public QDialog
+    {
+      Q_OBJECT
+
+    public:
+      explicit ConstraintsDialog(QWidget* parent_=0);
+      ~ConstraintsDialog() override;
+
+      void whow();
+
+    private:
+      Ui::ConstraintsDialog* ui;
+    };
+  }
+}
+#endif //AVOGADRO_QTPLUGINS_CONSTRAINTSDIALOG_H
diff --git a/avogadro/qtplugins/constraints/orig/constraintsdialog_orig.ui b/avogadro/qtplugins/constraints/orig/constraintsdialog_orig.ui
new file mode 100644
index 0000000000..42a3c2186d
--- /dev/null
+++ b/avogadro/qtplugins/constraints/orig/constraintsdialog_orig.ui
@@ -0,0 +1,225 @@
+<ui version="4.0" >
+ <class>Avogadro::QtPlugins::ConstraintsDialog</class>
+ <widget class="QDialog" name="Avogadro::QtPlugins::ConstraintsDialog" >
+  <property name="geometry" >
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>750</width>
+    <height>357</height>
+   </rect>
+  </property>
+  <property name="windowTitle" >
+   <string>Constraints</string>
+  </property>
+  <layout class="QVBoxLayout" >
+   <item>
+    <widget class="QTableView" name="ConstraintsTableView" >
+     <property name="selectionBehavior" >
+      <enum>QAbstractItemView::SelectRows</enum>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox" >
+     <property name="title" >
+      <string>Add Constraints</string>
+     </property>
+     <layout class="QHBoxLayout" >
+      <item>
+       <layout class="QHBoxLayout" >
+        <item>
+         <widget class="QLabel" name="label" >
+          <property name="maximumSize" >
+           <size>
+            <width>40</width>
+            <height>16777215</height>
+           </size>
+          </property>
+          <property name="text" >
+           <string>Type</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QComboBox" name="comboType" >
+          <item>
+           <property name="text" >
+            <string>Ignore Atom</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Fix Atom</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Fix Atom X</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Fix Atom Y</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Fix Atom Z</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Distance</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Angle</string>
+           </property>
+          </item>
+          <item>
+           <property name="text" >
+            <string>Torsion angle</string>
+           </property>
+          </item>
+         </widget>
+        </item>
+        <item>
+         <widget class="QLabel" name="label_2" >
+          <property name="text" >
+           <string>Constraint Value</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QDoubleSpinBox" name="editValue" />
+        </item>
+        <item>
+         <widget class="QLabel" name="label_3" >
+          <property name="text" >
+           <string>Atom Indices</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editA" />
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editB" />
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editC" />
+        </item>
+        <item>
+         <widget class="QSpinBox" name="editD" />
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsAdd" >
+          <property name="text" >
+           <string>Add</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox_2" >
+     <property name="title" >
+      <string>Options</string>
+     </property>
+     <layout class="QHBoxLayout" >
+      <item>
+       <layout class="QHBoxLayout" >
+        <item>
+         <widget class="QPushButton" name="ConstraintsSave" >
+          <property name="enabled" >
+           <bool>false</bool>
+          </property>
+          <property name="text" >
+           <string>Save</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsLoad" >
+          <property name="enabled" >
+           <bool>false</bool>
+          </property>
+          <property name="text" >
+           <string>Load</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <spacer>
+          <property name="orientation" >
+           <enum>Qt::Horizontal</enum>
+          </property>
+          <property name="sizeHint" >
+           <size>
+            <width>40</width>
+            <height>20</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsDelete" >
+          <property name="sizePolicy" >
+           <sizepolicy vsizetype="Fixed" hsizetype="Minimum" >
+            <horstretch>0</horstretch>
+            <verstretch>0</verstretch>
+           </sizepolicy>
+          </property>
+          <property name="minimumSize" >
+           <size>
+            <width>100</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="text" >
+           <string>Delete Selected</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsDeleteAll" >
+          <property name="text" >
+           <string>Delete All</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <spacer>
+          <property name="orientation" >
+           <enum>Qt::Horizontal</enum>
+          </property>
+          <property name="sizeHint" >
+           <size>
+            <width>40</width>
+            <height>20</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
+        <item>
+         <widget class="QPushButton" name="ConstraintsOK" >
+          <property name="text" >
+           <string>OK</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>