The relativistic valence shell effective Hamiltonian method for atomic and molecular systems

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.466358· OSTI ID:5259953

Shukla, A; Banerjee, A ^[1]

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1. Theory Project, Idaho National Engineering Laboratory, EG G Idaho, Inc., Idaho Falls, Idaho 83415-2208 (United States) Physics Department, Utah State University, Logan, Utah, 84322-4415 (United States)

A new [ital ab] [ital initio] method for fully relativistic (four-component Dirac many-body formalism) correlated electronic structure calculations, which makes explicit reference to valence electrons only, is presented for atomic and molecular processes in which the core electrons remain inert. The method exactly reproduces all properties (wave functions, energies, etc.) of an all electron calculation with frozen core wave functions and thus provides a great computational advantage. The method is based on constructing a valence Hamiltonian which includes a one-electron effective potential for the core--valence interactions. This interaction potential, which needs to be calculated once and for all, is exact for a chosen basis since it is constructed (all constituent local and nonlocal interactions) in matrix form in the current basis. This potential is used subsequently in valence-electron-only calculations, based on a novel algorithm, by constructing explicitly valence orbitals orthogonal to the core orbitals as linear combinations only among themselves. It has no adjustable parameters and no restrictions on the choice of basis sets. It yields considerable savings of computer time and space over the corresponding frozen core all-electron calculations. Dirac-Fock SCF calculations are presented for the ground states of closed- and open-shell atoms Li, Be, B, C, N, O, F, F[sup [minus]], Ne, Na[sup +], Na, Al, and S for demonstration.

• DOE Contract Number: AC07-76ID01570
• OSTI ID: 5259953
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 100:5; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664100* -- Theory of Electronic Structure of Atoms & Molecules-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
ALKALINE EARTH METALS
ALUMINIUM
ANIONS
ATOMS
BERYLLIUM
BORON
CALCULATION METHODS
CARBON
CATIONS
CHARGED PARTICLES
CORRELATIONS
DIFFERENTIAL EQUATIONS
DIRAC EQUATION
ELECTRON CORRELATION
ELECTRONIC STRUCTURE
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY LEVELS
ENERGY RANGE
EQUATIONS
FERMIONS
FLUIDS
FLUORINE
FLUORINE IONS
FUNCTIONS
GASES
GROUND STATES
HALOGENS
HAMILTONIANS
IONS
LEPTONS
LITHIUM
MANY-BODY PROBLEM
MATHEMATICAL OPERATORS
METALS
MOLECULES
NEON
NITROGEN
NONMETALS
OXYGEN
PARTIAL DIFFERENTIAL EQUATIONS
QUANTUM OPERATORS
RARE GASES
RELATIVISTIC RANGE
SEMIMETALS
SODIUM
SODIUM IONS
SULFUR
VALENCE
WAVE EQUATIONS
WAVE FUNCTIONS