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 functi ons of eight molecules and ions that are often believed to possess hyp ervalent 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 o rbitals''. Results of this detailed analysis, in which the first-order density matrices calculated at the MP2/6-311++G* level were employed , clearly show that the ionicity of bonds in the SO2, SO3, SO42-, PF5, PF4-, SF4, and SF6 species is large enough to make it unnecessary to invoke the notion of hypervalency. The only system among the species s tudied that could possibly be called hypervalent is ClF4+.