title: Lowest ^{2}S Electronic Excitations of the Boron Atom.
abstract: A theoretical ab initio approach for calculating bound states of small atoms is developed and implemented. The approach is based on finite-nuclear-mass [non-Born-Oppenheimer (non-BO)] nonrelativistic variational calculations performed with all-particle explicitly correlated Gaussian functions and includes the leading relativistic and quantum electrodynamics energy corrections determined using the non-BO wave functions. The approach is applied to determine the total and transition energies for the lowest four ^{2}S electronic excitations of the boron atom. The transition energies agree with the available experimental values within 0.2-0.3  cm^{-1}. Previously, such accuracy was achieved for three- and four-electron systems.
authors.affiliation: Department of Physics, School of Science and Technology, Nazarbayev University, Astana 010000, Kazakhstan.
authors.forename: Sergiy
authors.initials: S
authors.lastname: Bubin
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, USA.|Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Ludwik
authors.initials: L
authors.lastname: Adamowicz