Electronic and spatial structure of five-membered oxygen-or sulfur-containing cyclic phosphorus and arsenic compounds based on quantum-chemical calculations

We have carried out nonempirical quantum-chemical calculations for five-membered heterocyclic molecules containing O or S atoms and also P or As atoms in the ring, using RHF/6-31G(d) and MP2/6-31G(d) methods with full optimization of their geometry. We have studied their electronic and spatial structure and the characteristics of the interaction between atoms in the molecules. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 629–634 April, 2006.