Benchmark variational calculations of the four lowest ${}^{2}P$ and ${}^{2}S$ 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 $\delta$ 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.

• Received 20 December 2010

DOI:https://doi.org/10.1103/PhysRevA.83.022505