bool OEMDLHasParity(const OEMolBase &mol)
This function checks the MDL "ischiral" flag on a molecule. After
reading from an MDL connection table this value is true, if the chiral
flag was set in the header. After calling the OEMDLPerceiveParity
function this value is true, if a non-zero stereo parity value was
assigned to any atom.