Overlap as a Criterion for Conduction in the Cubic Tungsten Bronzes

Abstract
Overlap calculations using Slater orbitals with exponents adjusted to match SCF functions have been performed on eight pairs of orbitals which have been considered to have some pertinence to conduction in the cubic sodium tungsten bronzes. The results support the dπ—pπ model proposed by Sienko and by Good‐enough and clearly indicate where the overlap criterion alone breaks down, namely for the case of sodium—sodium pσ—pσ overlap.