OEGetDistance2

double OEGetDistance2(const OEMolBase &mol, const OEAtomBase *a,
                      const OEAtomBase *b)
double OEGetDistance2(const OEConfBase &conf, const OEAtomBase *a,
                      const OEAtomBase *b)
double OEGetDistance2(const OEMolBase &ma, const OEAtomBase *a,
                      const OEMolBase &mb, const OEAtomBase *b)
double OEGetDistance2(const OEConfBase &ca, const OEAtomBase *a,
                      const OEConfBase &cb, const OEAtomBase *b)

These four functions are almost identical to the OEGetDistance function. However, they return the square of the distance between two atoms rather than distance. When it is possible to use the square of the distance, this is more efficient.