diff --git a/CMakeLists.txt b/CMakeLists.txt
index eb15770e8b..0008bafc38 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,6 +29,11 @@ set(AvogadroLibs_VERSION
 find_package(Git)
 determine_version(${AvogadroLibs_SOURCE_DIR} ${GIT_EXECUTABLE} "AvogadroLibs")
 
+# path for data / fragment files which could be overriden by package maintainers
+# by default we assume we're using the openchemistry superbuild layout
+# .. this is used by the fragment library, molecules, crystals, etc.
+set(AvogadroLibs_SOURCEDATA_DIR "${AvogadroLibs_SOURCE_DIR}/..")
+
 option(BUILD_SHARED_LIBS "Build with shared libraries" ON)
 
 # Before any plugins are defined, and before any add_subdirectory calls:
diff --git a/avogadro/qtplugins/insertfragment/CMakeLists.txt b/avogadro/qtplugins/insertfragment/CMakeLists.txt
index 3484257ca9..4f4f3f0e41 100644
--- a/avogadro/qtplugins/insertfragment/CMakeLists.txt
+++ b/avogadro/qtplugins/insertfragment/CMakeLists.txt
@@ -10,8 +10,8 @@ avogadro_plugin(InsertFragment
 
 # Install the fragments & crystals
 # TODO - make this a for loop
-set(_molecules "${AvogadroLibs_SOURCE_DIR}/../molecules")
-set(_crystals "${AvogadroLibs_SOURCE_DIR}/../crystals")
+set(_molecules "${AvogadroLibs_SOURCEDATA_DIR}/molecules")
+set(_crystals "${AvogadroLibs_SOURCEDATA_DIR}/crystals")
 
 # Look in parallel directory for the molecule fragment repository
 if(NOT EXISTS "${_molecules}")
@@ -19,32 +19,32 @@ if(NOT EXISTS "${_molecules}")
 ExternalProject_Add(molecules
     GIT_REPOSITORY https://github.com/openchemistry/molecules
     # or https://github.com/OpenChemistry/molecules/archive/refs/heads/master.zip
-    SOURCE_DIR "${AvogadroLibs_SOURCE_DIR}/../molecules"
+    SOURCE_DIR "${AvogadroLibs_SOURCEDATA_DIR}/molecules"
     CONFIGURE_COMMAND ""
     BUILD_COMMAND ""
     INSTALL_COMMAND ""
 )
 endif()
 
-install(DIRECTORY "${AvogadroLibs_SOURCE_DIR}/../molecules"
+install(DIRECTORY "${AvogadroLibs_SOURCEDATA_DIR}/molecules"
   DESTINATION "${INSTALL_DATA_DIR}/avogadro2"
   PATTERN ".git" EXCLUDE
 )
 
 # crystals
 if(NOT EXISTS "${_crystals}")
-# download molecules... 
+# download molecules...
 ExternalProject_Add(crystals
     GIT_REPOSITORY https://github.com/openchemistry/crystals
     # or https://github.com/OpenChemistry/crystals/archive/refs/heads/master.zip
-    SOURCE_DIR "${AvogadroLibs_SOURCE_DIR}/../crystals"
+    SOURCE_DIR "${AvogadroLibs_SOURCEDATA_DIR}/crystals"
     CONFIGURE_COMMAND ""
     BUILD_COMMAND ""
     INSTALL_COMMAND ""
 )
 endif()
 
-install(DIRECTORY "${AvogadroLibs_SOURCE_DIR}/../crystals"
+install(DIRECTORY "${AvogadroLibs_SOURCEDATA_DIR}/crystals"
 DESTINATION "${INSTALL_DATA_DIR}/avogadro2"
 PATTERN ".git" EXCLUDE
 )
diff --git a/avogadro/qtplugins/templatetool/CMakeLists.txt b/avogadro/qtplugins/templatetool/CMakeLists.txt
index 3f68e6dd79..220108458f 100644
--- a/avogadro/qtplugins/templatetool/CMakeLists.txt
+++ b/avogadro/qtplugins/templatetool/CMakeLists.txt
@@ -24,7 +24,7 @@ avogadro_plugin(TemplateTool
 )
 
 # Install the fragments
-set(_fragments "${AvogadroLibs_SOURCE_DIR}/../fragments")
+set(_fragments "${AvogadroLibs_SOURCEDATA_DIR}/fragments")
 
 # Look in parallel directory for the molecule fragment repository
 if(NOT EXISTS "${_fragments}")
@@ -33,14 +33,14 @@ ExternalProject_Add(fragments
     GIT_REPOSITORY https://github.com/openchemistry/fragments
     GIT_TAG main
     # or https://github.com/OpenChemistry/molecules/archive/refs/heads/master.zip
-    SOURCE_DIR "${AvogadroLibs_SOURCE_DIR}/../fragments"
+    SOURCE_DIR "${AvogadroLibs_SOURCEDATA_DIR}/fragments"
     CONFIGURE_COMMAND ""
     BUILD_COMMAND ""
     INSTALL_COMMAND ""
 )
 endif()
 
-install(DIRECTORY "${AvogadroLibs_SOURCE_DIR}/../fragments"
+install(DIRECTORY "${AvogadroLibs_SOURCEDATA_DIR}/fragments"
   DESTINATION "${INSTALL_DATA_DIR}/avogadro2"
   PATTERN ".git" EXCLUDE
 )