THE GENERATOR-COORDINATE DIRAC-FOCK METHOD FOR OPEN-SHELL ATOMIC SYSTEMS

Recently we developed generator coordinate Dirac-Fock and Dirac-Fock-B reit methods for closed-shell systems assuming finite nucleus and have reported Dirac-Fock and Dirac-Fock-Breit energies for the atoms He th rough Nobelium (Z=102) [see Refs. 10-13]. In this paper, we generalize our earlier work on closed-shell systems and develop a generator coor dinate Dirac-Fock method for open-shell systems. We present results fb r a number of representative open-shell heavy atoms (with nuclear char ge Z>80) including the actinide and superheavy transactinide (with Z > 103) atomic systems: Fr (Z=87), Ac (Z=89), and Lr (Z=103) to E113 (eka -thallium, Z=113). The high accuracy obtained in our open-shell Dirac- Fock calculations is similar to that of our closed-shell calculations, and we attribute it to the fact that the representation of the relati vistic dynamics of an electron in a spherical ball finite nucleus near the origin in terms of our universal Gaussian basis set is as accurat e as that provided by the numerical finite difference method. The DF S CF energies calculated by Desclaux [At. Data. Nucl. Data Tables 12, 31 1 (1973)] (apart from a typographic error for Fr pointed out here) are higher than those reported here for atoms of some of the superheavy t ransactinide elements by as much as 5 hartrees (136 eV). We believe th at this is due to the use by Desclaux of much larger atomic masses tha n the currently accepted values for these elements. (C) 1998 American Institute of Physics. [S0021-9606(98)30544-9].