Collect. Czech. Chem. Commun. 1980, 45, 2194-2200

On applicability of CNDO/S-ci method to calculation of electronic spectra. 1-Methyl-3-carbamoylpyridinium cation and 1,4-dihydronicotinamide

Jiří Krechl and Josef Kuthan

Department of Organic Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6


Further arguments have been gathered to support the applicability (as a variable) of the parameter χ fixed by del Bene and Jaffe in the CNDO/S method. For the heteroaromatic ion I the value 0.585 suggested by these authors is suitable, but for the 1,4-dihydropyridine derivative II agreement between experimental a calculated spectrum can be obtained with χ 0.4. Furthermore, effects of the optimum molecular geometry and width of the configuration interaction on the results of the theoretical treatment are discussed.