Random tempering of Gaussian-type geminals. III. Coupled pair calculations on lithium hydride and beryllium

We use random tempering formulas and a sorting procedure to produce basis sets of explicitly correlated Gaussian-type geminals for the calculation of the coupled pair energies of the beryllium atom and lithium hydride. These energies show rapid convergence and are comparable to calculations which use a basis set where all nonlinear parameters have been optimized. Our complete coupled pair energies are 92.95 and 82.65 mhartree for Be and LiH, respectively. When combined with literature values for single and triple excitations, our results provide the most accurate ab initio calculated energies to date for Be and LiH.