Geometrical parameters of tetraatomic carbonyl molecules X 2 CO and XYCO (X, Y ϭ H, F, Cl) in the ground (S 0 ) and lowest excited singlet (S 1 ) and triplet (T 1 ) electronic states as well as values of barriers to inversion in S 1 and T 1 states and S 1 4 S 0 and T 1 4 S 0 adiabatic transition energies were systematically investigated by means of various quantumchemical techniques.

No abstract

Electronic structure of the low-lying excited states of the CH 3 NO molecule is considered. The detailed analysis of the first excited triplet and singlet states of this molecule is performed by different ab initio methods to estimate equilibrium geometry, barriers to internal rotation, harmonic frequencies, and adiabatic transition energies. Anharmonic vibrational approximations are also considered. The multidimensional VibSCF scheme and the 1-D variational method for the section of the potential energy surface along the torsion coordinate are used. Theoretical results are found to be in good agreement with experimental data.

No abstract

No abstract