Calculation of excited molecular states taking account of partial relaxation of the core

Effects of electron-core relaxation in the excitation of atomic systems are considered. A new approach to the consideration of relaxation is proposed, and the corresponding equations are obtained. In the -electron approximation, the first excited states of some organic molecules are calculated by the V^(N–1)-potential method, the Morokuma-Iwata method, and a method proposed in the present work.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 55–59, October, 1985.     

Semiempirical calculation of the excited states of several azabenzenes with the aid of the potential VN-1

Theoretical and Experimental Chemistry -     

Stability of the (H2O)2 dimer in the ground and lowest-lying excited electronic states

A theoretical study of the (H₂O)₂ dimer has been carried out in which the lowest S₁ and T₁ excited electronic states of the dimer complex, the influence of hydrogen bond formation on the shift in the maximum of the absorption band, and the stability of the dimer complex in the ground and excited states have been examined. It was found that there is only a single global maximum for the system — a nonplanar dimer complex formed by a linear hydrogen bond. Cyclic and bifurcated structures are transition states which do not form stable configurations when electronically excited. For the structure having a minimum in the ground electronic state, two nondissociating S₁ and T₁ states were found with bond energies of 2.0 and 4.4 kcal/mole, respectively. Formation of hydrogen bonds leads to a shift in the absorption maximum to the blue region with respect to the monomer. The hydrogen bond was found to weaken in the excited electronic states of the dimer.V. D. Kuznetsov Siberian Physicotechnical Scientific-Research Institute at the State University, Tomsk, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 11–15, March, 1993.     

The initial stage of self-reversal in a spectral line

The stage where a dip appears at the center is considered, for the general case of an unsymmetrical line. A graphical method is given for determining the parameters.We are indebted to N. G. Preobrazhenskii for a discussion of the results.     

Incorporation of doubly excited configurations in calculating the benzene-cyanoethylene complex

A calculation by Pople's method with configuration interaction is presented for the weak complex of benzene with tetracyanoethylene incorporating doubly excited configurations; the bond strength is found as 1.8 kcal/mole, as well as the contributions from the charge-transfer and dispersion forces. The energies of the first four transitions are calculated, the lowest of which are of charge-transfer type.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 16, No. 7, pp. 115–118, July, 1973.