Analysis of the correlating versus polarizing role of bond functions in CEPA-PNO computations of diazene

Abstract

Basis set expansion by inclusion of s and p-type gaussian functions centred on bond axes is shown to be effective in accounting for electronic relaxation due to correlation effects in molecular wavefunctions of diazene. This study demonstrates the effective correlating role of bond functions and so extends their established role as polarization functions. Extensive bond-function optimization at the CEPA level in diazene indicates that more restricted optimizations may be adequate in further studies.