Ensuring derivatives are not added in ContactMap when they are not required

Author: Gareth Aneurin Tribello

src/adjmat/ContactMatrix.cpp

@@ -113,6 +113,7 @@ double ContactMatrix::calculateWeight( const Vector& pos1, const Vector& pos2, c
   if( mod2<epsilon ) return 0.0;  // Atoms can't be bonded to themselves
   double dfunc, val = switchingFunction.calculateSqr( mod2, dfunc );
   if( val<epsilon ) return 0.0;
+  if( doNotCalculateDerivatives() ) return val;
   addAtomDerivatives( 0, (-dfunc)*distance, myvals );
   addAtomDerivatives( 1, (+dfunc)*distance, myvals );
   addBoxDerivatives( (-dfunc)*Tensor(distance,distance), myvals );