Accurate ab initio potential energy curve of O2. I. Nonrelativistic full configuration interaction valence correlation by the correlation energy extrapolation by intrinsic scaling method.
Accurate ab initio potential energy curve of O2. I. Nonrelativistic full configuration interaction valence correlation by the correlation energy extrapolation by intrinsic scaling method.
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DOI：
10.1063/1.3298373
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发表时间：
2010-02
期刊：
影响因子：
--
通讯作者：
L. Bytautas;K. Ruedenberg
中科院分区：
文献类型：
--
作者：
L. Bytautas;K. Ruedenberg
用新近提出的内禀标度关联能外推法计算了O（2）分子价层中沿基态（3）σ（g）（-）势能曲线在0.9 ~ 6 A的24个核间距沿着处的非相对论电子关联，平衡距离为1.207 52 A.用Dunning的三重和四重zeta相关一致基组，确定了全组态相互作用能，其精度约为0.3martree，通过相对于沿着反应路径强烈变化的多构型参考函数连续产生高达六重激发，参考函数的能量和相对于这些参考函数的相关能的能量被外推到其完整的基础设置限制。
The recently introduced method of correlation energy extrapolation by intrinsic scaling is used to calculate the nonrelativistic electron correlations in the valence shell of the O(2) molecule at 24 internuclear distances along the ground state (3)Sigma(g)(-) potential energy curve from 0.9 to 6 A, the equilibrium distance being 1.207 52 A. Using Dunning's correlation-consistent triple- and quadruple-zeta basis sets, the full configuration interaction energies are determined, with an accuracy of about 0.3 mhartree, by successively generating up to sextuple excitations with respect to multiconfigurational reference functions that strongly change along the reaction path. The energies of the reference functions and those of the correlation energies with respect to these reference functions are then extrapolated to their complete basis set limits.