Ground states of conjugated molecules. XVII. The l.c.a.o. s.c.f. m.o. treatment of compounds containing nitrogen and oxygen

In a recent paper (Dewar & Harget 1970) we described an l.c.a.o. s.c.f. m.o. treatment which gave an extremely good account of the ground-state properties of conjugated hydrocarbons. This treatment differed from the previous procedure used in this department, in that the one-electron core resonance integral B is evaluated using theMulliken approximation, B = KS. We now describe an extension of this treatment to conjugated molecules containing nitrogen or oxygen. Calculated heats of atomization and bond lengths are given for some nitrogen and oxygen compounds, and are in good agreement with experimental data.