Gold atom Local maximum of relativistic effects

CCSD transition energies in Au (eV). IP is the ionization potential, EA denotes electron affinity, and EE — excitation energy relative to the ground state. FS denotes fine-structure splittings. 

The basis consisted of 21sl7plld7/ Gaussian spinors [67], and correlated shells included 4 spdf5spd6s. Table 11 shows the nonrelativistic, Dirac-Coulomb, and Dirac-Coulomb-Breit total energies of the two ions. As expected, relativistic effects are very large, over 1100 haxtree. The nonadditivity of relativistic and correlation corrections to the energy, apparent in Table 11, has been noted above. 

The MCDF calculations [69] involved between 354 and 1708 CSFs for the different J states. The number of CSFs was much larger in the CC calculations [70], since all excitations from the 4spdf5sp orbitals to virtual orbitals (except virtuals with energies above 100 hartree), as well as excitations from 4spd5sp to the partially filled 4/, were included. Thus, a much larger part of dynamic correlation was accounted for. The Pr + closed shell state served as reference, and two electrons were added in the 4/ shell to obtain the levels of interest. Three basis sets were used, with I going up to 4, 5 and 6. The calculated excitation energies are compared with experiment [68] in Table 13. 

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