Quantum chemistry by random walk: Importance sampling for H+3
Quantum chemistry by random walk: Importance sampling for H+3
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随机游走的量子化学：H 3 的重要性采样
DOI：
10.1063/1.441022
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发表时间：
1981
影响因子：
4.4
通讯作者：
James B. Anderson
中科院分区：
文献类型：
--
作者：
F. Mentch;James B. Anderson
使用重要性抽样与随机行走方法解决薛定谔方程的方式设计的Ceperley检查在其应用中确定基态H +3的电子能量。改进后的方法产生的能量比以前的随机行走或变分计算更高的精度。所需的计算工作量仍然很大的高精度，但可能会减少重要性采样中使用的改进的试验波函数。对于边长为1.6500 a.u.的等边三角形构型，计算的总能量为− 1.3439 ± 0.0002 a.u。这个值低于-1.34335 a.u.的上限。在Salmon和Poshusta的最低能量变分计算中建立，高于他们的估计值-1.3447 a.u。作为真正的价值。在确定H +3的振动频率时，对其他四种感兴趣的核构型计算的能量通常为0.001至0.003 a.u。低于最精确的变分计算
The use of importance sampling with the random‐walk method of solving the Schrodinger equation in a way devised by Ceperley is examined in its application to determining the electronic energy of ground state H+3. The improved method yields energies of higher accuracy than prior random‐walk or variational calculations. The required computation effort remains large for high accuracy but might be reduced by improved trial wave functions used in importance sampling. For the equilateral triangle configuration with side length of 1.6500 a.u., the calculated total energy is −1.3439±0.0002 a.u. This value lies below the upper bound of −1.34335 a.u. established in the lowest‐energy variational calculations by Salmon and Poshusta and above their estimate of −1.3447 a.u. as the true value. Energies calculated for four other nuclear configurations of interest in determining the vibrational frequencies of H+3 are found to be, typically, 0.001 to 0.003 a.u. lower than those of the most accurate variational calculations...