Valence quantum Monte Carlo with ab initio effective core potentials

Journal Article · Wed Jul 15 04:00:00 EDT 1987 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.453345· OSTI ID:6495235

Hammond, B L; Reynolds, P J; Lester, Jr, W A

Effective-core potentials (ECP's) obtained from ab initio methods are implemented in molecular quantum Monte Carlo (QMC). The theory is presented, and applied to the calculation of electron affinities (EA) of Li and Na, the ionization potential (IP) of Mg, the binding energies (D/sub e/) of NaH and Na/sub 2/, and the potential energy curve of Na/sub 2/. In all cases ECP--QMC results are found to be as accurate as previous all-electron results. In particular, the calculated quantities (vs experimental values) are (in eV): EA(Li) = 0.611 +- 0.020 (0.620), EA(Na) = 0.555 +- 0.021 (0.546), IP(Mg) = 7.637 +- 0.026 (7.646), D/sub e/ (NaH) = 1.954 +- 0.073 (1.971), and D/sub e/ (Na/sub 2/) = 0.746 +- 0.020 (0.747). In addition, the statistical precision obtained surpasses that which can be readily achieved in all-electron QMC calculations on these systems.

• Research Organization: Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6495235
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 87:2; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
AFFINITY
ALKALI METAL COMPOUNDS
ALKALI METALS
ALKALINE EARTH METALS
BINDING ENERGY
DIMERS
ELECTRONEGATIVITY
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY
HYDRIDES
HYDROGEN COMPOUNDS
IONIZATION POTENTIAL
LITHIUM
MAGNESIUM
MECHANICS
METALS
MONTE CARLO METHOD
QUANTUM MECHANICS
SODIUM
SODIUM COMPOUNDS
SODIUM HYDRIDES