Correlation energies in polyatomic molecules modelled in terms of bond order

Earlier work has used the concepts of density functional theory to achieve useful estimates of both atomic and diatomic molecular correlation energies. In the present work, some of these ideas are combined with more conventional chemical ideas relating to bond order to evaluate correlation energies in some thirty polyatomic molecules. There are a number of empirical parameters in the present modelling process, but once these are fixed on some 16 molecules the correlation energies in the remaining molecules follow quantitatively, without any adjustments.