Nonempirical electron-correlation calculations on ALi/sub k/ and Ali/sub k+1//sup +/ clusters formed with elements from the second and third periods
Several basic sets have been used (from 3-21 G/sub A//asterisk/ to DZHD + P/sub A/) with electron correlation in the Meller-Plesset MP3 approximation in nonempirical calculations on ALi/sub k+1//sup +/ and ALi/sub K+1//sup +/ lithium clusters (CLi/sub 2/, CLi/sub 3//sup +/, NLi/sub 3/, NLi/sub 4//sup +/, OLi/sub 2/, OLi/sub 3//sup +/, etc.) formed with elements from the second and third periods in the lowest singlet states. A study has been made on the effects of the approximation on the results. Several reference systems are used to show that the SCF/3-21G/sub A//asterisk/ approximation describes the lithide geometry satisfactorily, while MP3/DZHD + P/sub A/ gives a satisfactory description of the affinity of Ali/sub k/ for Li/sup +/. These approximations have been taken as optimal for calculations on the other compounds. The Li/sup +/ affinities are highest for NLi/sub 3/ and PLi/sub 3/ (90 and 84 kcal correspondingly) and decrease as A varies along the subgroups from the second to the third and the lower sp periods, as well as when A varies in each period from the middle to the start or end. The affinities of the analogous compounds for Na/sup +/ are less by 5-10 kcal than those for Li/sup +/. The values are compared with the proton affinities for the related hydrides AK/sub k/.
- OSTI ID:
- 5820712
- Journal Information:
- J. Struct. Chem. (Engl. Transl.); (United States), Journal Name: J. Struct. Chem. (Engl. Transl.); (United States) Vol. 29:3; ISSN JSTCA
- Country of Publication:
- United States
- Language:
- English
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657002 -- Theoretical & Mathematical Physics-- Classical & Quantum Mechanics
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AFFINITY
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ARGON COMPOUNDS
ATOMIC MODELS
BERYLLIUM COMPOUNDS
BINDING ENERGY
BORON COMPOUNDS
CARBON COMPOUNDS
CHARGE DISTRIBUTION
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ELECTRON CORRELATION
ELECTRON DENSITY
ELECTRONIC STRUCTURE
ENERGY
LITHIUM COMPOUNDS
MAGNESIUM COMPOUNDS
MATHEMATICAL MODELS
MATHEMATICS
MECHANICS
NEON COMPOUNDS
NITROGEN COMPOUNDS
OPTIMIZATION
ORIENTATION
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
QUANTUM MECHANICS
RARE GAS COMPOUNDS
SELF-CONSISTENT FIELD
SET THEORY
SILICON COMPOUNDS
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