Calculations of potential energy surfaces using Monte Carlo configuration interaction
Calculations of potential energy surfaces using Monte Carlo configuration interaction
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DOI：
10.1063/1.4767052
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发表时间：
2012-11-21
影响因子：
4.4
通讯作者：
Paterson, Martin J.
中科院分区：
文献类型：
--
作者：
Coe, Jeremy P.;Taylor, Daniel J.;Paterson, Martin J.
我们应用蒙特卡罗组态相互作用（MCCI）的方法计算了一系列小分子的基态势能曲线，并与全组态相互作用的结果进行了比较。我们表明，MCCI势能曲线可以计算出相对较高的精度，使用非平行误差进行量化，仅使用全构型相互作用空间的很小一部分。在大多数情况下，势曲线比其组成的单点能量更精确。最后，我们在超过全构型相互作用的基集系统上测试了MCCI程序：一个由50个氢原子和乙烯组成的晶格。乙烯的结果与其他计算工作相当一致，而对于50个氢的晶格，我们发现我们能够考虑的全构型相互作用空间的比例似乎太小，尽管再现了一些定性特征，但势曲线不太准确。(C) 2012年美国物理研究所。[http://dx.doi.org/10.1063/1.4767052]
We apply the method of Monte Carlo configuration interaction (MCCI) to calculate ground-state potential energy curves for a range of small molecules and compare the results with full configuration interaction. We show that the MCCI potential energy curve can be calculated to relatively good accuracy, as quantified using the non-parallelity error, using only a very small fraction of the full configuration interaction space. In most cases the potential curve is of better accuracy than its constituent single-point energies. We finally test the MCCI program on systems with basis sets beyond full configuration interaction: a lattice of 50 hydrogen atoms and ethylene. The results for ethylene agree fairly well with other computational work while for the lattice of 50 hydrogens we find that the fraction of the full configuration interaction space we were able to consider appears to be too small as, although some qualitative features are reproduced, the potential curve is less accurate. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4767052]