Zobrazeno 1 - 10
of 36
pro vyhledávání: '"Stanley A Hagstrom"'
Autor:
Stanley A. Hagstrom, James S. Sims
Publikováno v:
Journal of Physics B: Atomic, Molecular and Optical Physics. 40:1575-1587
Three-electron kinetic energy and electron?nucleus interaction integrals arising in Hylleraas?configuration interaction (Hy?CI) calculations are discussed. We show that the electron?nucleus interaction operators introduce no new integral complication
Autor:
James S Sims, Stanley A Hagstrom
Publikováno v:
Journal of Physics B: Atomic, Molecular and Optical Physics. 37:1519-1540
Autor:
Stanley A. Hagstrom, James S. Sims
Publikováno v:
International Journal of Quantum Chemistry. 90:1600-1609
Hylleraas-configuration interaction (Hy-CI) method variational calculations with up to 4648 expansion terms are reported for the ground 1 S state of neutral helium. Convergence arguments are presented to obtain estimates for the exact nonrelativistic
Autor:
James S, Sims, Stanley A, Hagstrom
Publikováno v:
The Journal of chemical physics. 140(22)
In a previous work, Sims and Hagstrom ["Hylleraas-configuration-interaction study of the 1 (1)S ground state of neutral beryllium," Phys. Rev. A 83, 032518 (2011)] reported Hylleraas-configuration-interaction (Hy-CI) method variational calculations f
Autor:
Stanley A. Hagstrom, JW Liu
Publikováno v:
Physical Review A. 50:3181-3185
Autor:
James S. Sims, Stanley A. Hagstrom
Publikováno v:
Physical Review A. 83
Hylleraas-configuration-interaction (Hy-CI) method variational calculations are reported for the ${}^{1}S$ ground state of neutral beryllium. The best nonrelativistic energy obtained was $\ensuremath{-}14.667 356 4$ hartree, which is estimated to be
Autor:
Stanley A. Hagstrom, James S. Sims
Publikováno v:
Physical Review A. 80
High-precision Hylleraas-configuration-interaction (Hy-CI) method variational calculations are reported for the $2\text{ }^{2}S$ ground state of neutral lithium. The nonrelativistic energy is calculated to be $\ensuremath{-}7.478\text{ }060\text{ }32
Autor:
Verena Meiser Umar, Charlotte Froese Fischer, Ernest R. Davidson, Stanley A. Hagstrom, Subhas J. Chakravorty
Publikováno v:
Physical Review A. 44:7071-7083
Improved estimates of the nonrelativistic stationary nucleus correlation energies of the ground-state atomic ions with three to ten electrons and Z up to 20 are derived by combining experimental data and improved ab initio calculations. Unlike previo
Autor:
James S. Sims, Stanley A. Hagstrom
Publikováno v:
Journal of Physics B: Atomic, Molecular and Optical Physics. 48:175003
The most difficult integral arising in Hylleraas-configuration interaction (Hy-CI) calculations, the three-electron triangle integral, is discussed. We focus on recursive techniques at both the double precision and quadruple precision level of accura
Autor:
James S. Sims, Stanley A. Hagstrom
Publikováno v:
Physical Review A. 68