Correlated-Gaussian calculations of the ground and low-lying excited states of the boron atom

Abstract

Benchmark variational calculations of the four lowest 2P and 2S states of the boron atom (including the ground state) have been performed. The wave functions of the states have been expanded in terms of all-particle explicitly correlated Gaussian basis functions and the finite mass of the nucleus has been explicitly accounted for.Variational upper bounds for the nonrelativistic finite- and infinite-nuclear-mass energies of all considered states have been obtained with the relative convergence of the order of 10−7–10−8. Expectation values of the powers of the inter-particle distances and Dirac δ functions depending on those distances have also been computed. These calculations provide reference values that can be used to test other high-level quantum chemistry methods