Rigorous interpretation of electronic wave functions. 2. Electronic structures of selected phosphorus, sulfur, and chlorine fluorides and oxides

Rigorous interpretive tools are used to analyze electronic wave functions of eight molecules and ions that are often believed to possess hypervalent electronic structures. The atomic charges, localized orbitals, and covalent bond orders are calculated in a consistent manner that does not rely on arbitrary references to basis functions as «atomic orbitals». Results of this detailed analysis, in which the first-order density matrices calculated at MP2/6-311++G ** level were employed, clearly show that the ionicity of bonds in the SO 2 , SO 3 , SO 4 2- , PF 5 , PF 4 - , SF 4 , and SF 6 species is large enough to make it unnecessary to invoke the notion of hypervalency