New model core potentials for gold.

Four model core potentials (MCPs) for gold were developed using results from the third-order Douglas-Kroll-Hess relativistic all-electron calculations. The MCPs were developed with four different valence spaces, ranging from the 5p, 5d, and 6s orbitals to 5s, 4f, 5p, 5d, and 6s orbitals. The new MCPs were applied in the calculations of atomic properties and potential energy curves of AuH and Au(2). Results indicate that the 4f orbital may be excluded but the 5s orbital must be included in the valence space because of the importance of 5s-6s electron correlation. The model core potential that has the valence space comprising the 5s, 5p, 5d, and 6s orbitals is considered to be the most accurate and efficient of these new potentials.