Equilibrium inversion barrier of NH3 from extrapolated coupled-cluster pair energies

被引：59

作者：

Klopper, W

Samson, CCM

Tarczay, G

Császár, AG

机构：

[1] Univ Utrecht, Debye Inst, Theoret Chem Grp, NL-3508 TB Utrecht, Netherlands

[2] Eotvos Lorand Univ, Dept Theoret Chem, H-1518 Budapest 112, Hungary

来源：

JOURNAL OF COMPUTATIONAL CHEMISTRY | 2001年 / 22卷 / 13期

关键词：

basis-set convergence; pair energies; coupled-cluster theory; inversion barrier; ammonia;

D O I：

10.1002/jcc.1088

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The basis-set convergence of singlet and triplet pair energies of coupled-cluster theory including single and double excitations is accelerated by means of extrapolations based on the distinct convergence behaviors of these pairs. The new extrapolation procedure predicts a nonrelativistic Born-Oppenheimer inversion barrier of 1767 +/- 12 cm(-1) for NH3. An effective one-dimensional, vibrationally averaged barrier of 2021 +/- 20 cm(-1) is obtained when relativistic effects (+20 m(-1)), Born-Oppenheimer diagonal corrections (-10 cm(-1)), and zero-point vibrations (+244 cm(-1)) are accounted for. (C) 2001 John Wiley & Sons, Inc.

引用

页码：1306 / 1314

页数：9

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