OESameChain

bool OESameChain(const OEAtomBase& atom1, const OEAtomBase& atom2)
bool OESameChain(const OEResidue& res1, const OEResidue& res2)

Determines whether two atoms or their respective OEResidue s are in the same chain. This returns true if both residues have the same NMR model number, OEResidue::GetModelNumber, and the same chain identifier, OEResidue::GetChainID.