# Theory of Molecular Photoabsorption

A general theoretical approach for computation of the molecular structure is developed and programmed. Its is based on the single-center representation of occupied, virtual and continuum molecular orbitals. The core occupied orbitals are obtained as solutions of MO LCAO problem and then represented via single-center expansion. The discrete and continuum electronic wave functions are solutions of the system of coupled differential equations for the radial parts of partial waves. Solution of the system is based on the R-matrix approach. The numerical solutions are further renormalized in order to describe a physically observed partial electronic waves in the asymptotic. The computed single electron wave functions generate an efficient basis for subsequent inclusion of many-electron correlations. The nuclear motion is described by solution of systems of coupled differential equations for the nuclear vibrational wave functions in the adiabatic and diabatic approaches. The developed theoretical approach is applied to study the most presented in the Earth's atmosphere diatomic molecules, e.g., O_{2}, N_{2}, NO, and CO.

*Cooperations:* Prof. Dr. V.L. Sukhorukov, Prof. Dr. I.D. Petrov and

Prof. Dr. B.M. Lagutin (Rostov State University of Transport Communications, Rostov-on-Don, Russia), Prof. Dr. A. Ehresmann (University of Kassel, Germany)* Status:* in progress