L.S. Khaikin, O.E. Grikina, M. Alcolea Palafox
Journal of Molecular Structure (THEOCHEM), (in print)
ABSTRACT. Ab initio RHF and MP2 force fields were calculated for chloramide with the use of the 6-31G*, 6-31G**, and 6-311G** basis sets. The obtained ab initio force fields were scaled by fitting to the available experimental vibrational frequencies for the H2NCl, H2N37Cl, and HDNCl species. This makes it possible to extend the set of transferable scale factors we recommended earlier. The difference between the scaled MP2 and RHF force fields is minimal, although the ab initio data themselves are improved by the inclusion of electron correlation. The effect produced by empirical anharmonisity corrections to the observed NH(ND) stretching frequencies upon the results of the fitting was tested. The experimentally observed satellite for the 1032 cm-1 band in the parent substance infrared spectrum should probably be attributed to the presence of HNCl2 in the sample, and does not refer to some vibrations of H2NCl or any of its isotopomers.