Extended Hueckel $beta$ parameters applied to diatomic molecules

From international symposium on atomic, molecular, solidstate theory, and quantum statistics; Sanibel lsland, Florida, USA (20 Jan 1974). Atom-atom separations predicted by extended Huckel theory using four BETA parameter approximations are compared for 15 diatomic molecules. Equilibrium separations R/ sub e/ determined from a new proposed formula for the BETA parameter are compared with R/sub e/'s resulting from the Mulliken-Wolfsberg-Helmholtz, Cusachs, and Jug BETA formulas. Results show that the new BETA formula is best in its prediction of R/sub e/'s. The new formula has the required property of yielding rotationally invariant results. (auth