KINETIC BALANCE AND VARIATIONAL BOUNDS FAILURE IN THE SOLUTION OF THE DIRAC-EQUATION IN A FINITE GAUSSIAN-BASIS SET

We have investigated bounds failure in calculations using Gaussian basis sets for the solution of the one-electron Dirac equation for the 2p 1 2 state of Hg79+. We show that bounds failure indicates inadequacies in the basis set, both in terms of the exponent range and the number of functions. We also show that over-representation of the small component space may lead to unphysical results. We conclude that it is important to use matched large and small component basis sets with an adequate size and exponent range. © 1990.