private boolean isCisTransEndPoint ( int idx ) { IAtom atom = container . getAtom ( idx ) ; // error: uninit atom if ( atom . getAtomicNumber ( ) == null || atom . getFormalCharge ( ) == null || atom . getImplicitHydrogenCount ( ) == null ) return false ; final int chg = atom . getFormalCharge ( ) ; final int btypes = getBondTypes ( idx ) ; switch ( atom . getAtomicNumber ( ) ) { case 6 : // C case 14 : // Si case 32 : // Ge // double, single, single return chg == 0 && btypes == 0x0102 ; case 7 : // N if ( chg == 0 ) // double, single return btypes == 0x0101 ; if ( chg == + 1 ) // double, single, single return btypes == 0x0102 ; default : return false ; } }
Checks if the atom can be involved in a double - bond .