New Scaled Atomshyphen;inhyphen;Molecules Theory for Predicting Diatomic Potentialhyphen;Energy Curves. I. General Theory and Application to H2and He2+ +

摘要

An exact scaled atomshyphen;inhyphen;molecules theory for predicting potentialhyphen;energy curves and other properties of diatomic molecules is developed. The basis consists, in the first place, of linear combinations of antisymmetrized products of atomic substate eigenfunctions. Each such basis function psgr;ncan be modified by introducing variational scaling parameterssnAandsnBinto its component atomic eigenfunctions. Exact equations are developed for determining, by reference to experimental atomic properties, all intrahyphen;atomic contributions to the energy matrix elements. All remaining parts of the energy matrix elements are interatomic in nature, and these parts are computed using previously determined approximate atomic eigenfunctions; as the latter are successively made more accurate, results of the diatomic calculation should converge to experiment. A restricted orbital model, which reduces the number of independent nonlinear variational parameters, is also proposed. Initial applications to ground and excited electronic state of H2and He2+ +are presented. A potentially useful approximate calibration technique is suggested and tested.