Benchmark calculations with correlated molecular wave functions .12. Core correlation effects on the homonuclear diatomic molecules B-2-F-2

被引:126
作者
Peterson, KA [1 ]
Wilson, AK [1 ]
Woon, DE [1 ]
Dunning, TH [1 ]
机构
[1] PACIFIC NW NATL LAB,ENVIRONM MOL SCI LAB,RICHLAND,WA 99352
关键词
molecular wave functions; core correlation effects; homonuclear diatomic molecules;
D O I
10.1007/s002140050259
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Using systematic sequences of the newly developed correlation consistent core-valence basis sets from cc-pCVDZ through cc-pCV6Z, the spectroscopic constants of the homonuclear diatomic molecules containing first row atoms, B-F, are calculated both with and without inclusion of 1s correlation. Internally contracted multireference configuration interaction (IC-MRCI) and singles and doubles coupled cluster (CCSD) theory with a perturbational estimate of connected triple excitations, CCSD(T), have been investigated. By exploiting the convergence of the correlation consistent basis sets, complete basis set (CBS) limits have been estimated for total energies, dissociation energies, equilibrium geometries, and harmonic frequencies, Based on the estimated CBS limits the effects of 1s correlation on D-e (kcal/mol), r(e) (Angstrom), and omega(e) (cm(-1)) are: +1.1, -0.0070, +10 for B-2; +1.5, -0.0040, +13 for C-2; +0.9, -0.0020, +9 for N-2; +0.3, -0.0020, +6 for O-2; and -0.1, -0.0015, +1 for F-2.
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页码:251 / 259
页数:9
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