Chemical deductions made using valency interaction formulas, VIF, compared with quantitative computer calculations for: (1)~main group hydrides, (2)~hypervalent carbocations, (3)~study of 1,3 hydrogen transfer reactions

Valency Interaction Formulas, VIF's, are applied to chemical species of long-standing interest. The qualitative energy level patterns, LPI, of main group hydrides are derived. From these, insight is gained into the HOMO-LUMO reactivities and VSEPR effects. The LPI derived using two VIF rules corresponds to calculated MO energies with the appropriate invariant quantity subtracted. Comparisons made between this LPI and EHT, EHTD, HF/STO-3G, HF/6-13G;Consequently, the relative stabilities of CH...