Ab initio effective core potentials for molecular calculations. II. All-electron comparisons and modifications of the procedure

Journal Article · Sat Apr 01 04:00:00 EST 1978 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.436172· OSTI ID:5076699

Hay, P J; Wadt, W R; Kahn, L R

Recently methods have been developed (L. R. Kahn, P. Baybutt, and D. G. Truhlar, J. Chem. Phys. 65, 3826 (1976)) to replace the core electrons of atoms by ab initio effective core potentials (ECP). Valence-electron calculations are reported on the ground states of HF, F/sub 2/, HCl, LiCl, and Cl/sub 2/ using ECP's for F and Cl, and the results are compared to all-electron calculations. Significant discrepancies are found (as much as 20 kcal/mol for D/sub e/ and 0.3 bohr for R/sub e/ in the case of Cl/sub 2/) between the two sets of calculations. The original formulation of generating ECP's can lead to artificial attractive tails in the potential at large values of r which leads to potential energy curves which are too attractive. The procedure of generating ECP's is modified to remove the long-range attractive tails. Excellent agreement between the valence-electron and all-electron calculations is then obtained.

• Research Organization: Theoretical Division, Los Alamos Scientific Laboratory, University of California, Los Alamos, New Mexico 87545
• OSTI ID: 5076699
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 68:7; ISSN JCPSA
• Country of Publication: United States
• Language: English

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74 ATOMIC AND MOLECULAR PHYSICS
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BINDING ENERGY
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CHLORINE
CHLORINE COMPOUNDS
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY
FLUORINE
HALIDES
HALOGEN COMPOUNDS
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HYDROCHLORIC ACID
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
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LITHIUM CHLORIDES
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