Calculations of electronic structure of molecules and complexes by the modified horn-murrel method

We describe the characteristic features of the VAI and VSAI calculation schemes, designed for nonempirical valence-basis calculations of the electronic structure of molecules and complexes and carried out using the program KOMPLEKS-2. The calculation results presented demonstrate good agreement with all-electron calculations. We show that the approximate VSAI method reproduces sufficiently satisfactorily the Hartree-Fock-Roothaan calculations.Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 25, No. 4, pp. 427–432, July–August, 1989.