Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom.
J Chem Phys. 2014 May 21;140(19):194106. doi: 10.1063/1.4875517.
We have used a generalised coherent state resolution of the identity to map the quantum canonical statistical average for a general system onto a phase-space average over the centre and width parameters of a thawed Gaussian wave packet. We also propose an artificial phase-space density that has the same behaviour as the canonical phase-space density in the low-temperature limit, and have constructed a novel Nosé-Hoover looped chain thermostat that generates this density in conjunction with variational thawed Gaussian wave-packet dynamics. This forms a new platform for evaluating statistical properties of quantum condensed-phase systems that has an explicit connection to the time-dependent Schrödinger equation, whilst retaining many of the appealing features of path-integral molecular dynamics.
我们使用广义相干态对易关系将一般系统的量子正则统计平均值映射到解冻高斯波包的中心和宽度参数上的相空间平均值。我们还提出了一种人工相空间密度,它在低温极限下具有与正则相空间密度相同的行为,并构建了一种新的诺瑟-胡佛循环链式恒温器,该恒温器与变分解冻高斯波包动力学一起产生这种密度。这为评估量子凝聚相系统的统计性质提供了一个新的平台,它与含时薛定谔方程有明确的联系,同时保留了路径积分分子动力学的许多吸引人的特点。