A GENERATOR-COORDINATE VERSION OF THE CLOSED-SHELL DIRAC-FOCK EQUATIONS

A generator coordinate version of the Dirac-Fock equations for relativ istic closed-shell atoms is presented. The integration of the Dirac-Fo ck equations is performed through the integral discretization techniqu e so as to preserve the continuous character of the generator coordina te formalism. With the new formalism we generate a universal Gaussian basis set for relativistic closed-shell atoms with d and f orbitals (z inc up to nobelium). The results obtained with the universal Gaussian basis set for Dirac-Fock-Coulomb self-consistent-held energies are com pared with numerical-finite-difference results and Dirac-Fock-Coulomb energies obtained by using other Gaussian basis sets. The excellent pe rformance of our universal Gaussian basis set is attributed to the int egral discretization technique of the generator coordinate Dirac-Fock method, as with it we are capable of generating Gaussian-type function exponents that are able to represent properly the relativistic kinema tics of an electron inside the nucleus. (C) 1996 American Institute of Physics.