Pair correlation effects in the relativistic many-body calculation of atomic polarizabilities

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6099001

Liu, Z

An approach for the accurate calculation of atomic properties is developed using a two-step procedure to generalize the coupled-cluster method to apply a relativistic many-body Hamiltonian with two interaction terms. Calculations are performed at the pair-correlation approximation level. The first step in the procedure is to solve for the single- and pair-excitations correlation operator with the electron-electron Coulomb interaction. Then with the resulting Brueckner orbitals and pair functions, the authors for the second correlation operator corresponding to the additional perturbation interaction. The calculations include the most significant correlation effects caused by the single- and pair-excitations to essentially all orders in perturbation theory. The procedure is tested on the ground-state energy and static dipole polarizability of helium. Results are in good agreement with Hylleraas coordinate calculations. Numerical calculations are carried out for valence ionization energies, hyperfine splittings, oscillator strengths and static polarizabilities for lithium, sodium and cesium. Results are reported for the Stark scalar and vector off-diagonal polarizabilities of Cs, which are important for the calibration of the measurement of parity nonconserving amplitudes in Cs. The importance of pair correlation effects in all of the atoms considered is discussed. The results show that an ab-initio description of atomic properties within the pair approximation is able to make predictions accurate at the 1{approx}2% level for Cs, and 0.1{approx}0.5% for Li and Na.

• Research Organization: Notre Dame Univ., IN (USA)
• OSTI ID: 6099001
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
BRUECKNER METHOD
CALCULATION METHODS
CESIUM
CORRELATIONS
COULOMB FIELD
ELECTRIC FIELDS
ELECTRICAL PROPERTIES
ELEMENTS
ENERGY LEVELS
FIELD THEORIES
FLUIDS
GASES
GENERAL RELATIVITY THEORY
GROUND STATES
HAMILTONIANS
HELIUM
LITHIUM
MANY-BODY PROBLEM
MATHEMATICAL OPERATORS
METALS
NONMETALS
PERTURBATION THEORY
PHYSICAL PROPERTIES
POLARIZABILITY
QUANTUM OPERATORS
RARE GASES
RELATIVITY THEORY
SODIUM