A Semi-empirical Analysis of the Electronic Spectra and Molecular Structures of Hydrogen Cyanide and Carbon Dioxide

Abstract

All valence electron molecular orbital calculations have been carried out on hydrogen cyanide and carbon dioxide using a minimum basis set of Slater-type orbitals by a semi-empirical SCF-LCAO-MO method described earlier for formaldehyde. Since many of the excited states of these molecules are bent, a series of calculations is carried out on hydrogen cyanide in the linear configuration and in bent configurations with H—C—N angles of 150°, 120°, and 90°, and on carbon dioxide in the linear configuration and bent configuration with O—C—O angle of 90°. The binding energy changes in various molecular orbitals on bending are used to interpret electronic spectra and are also compared with Walsh's curves.