Ballard Andrew J, Wales David J
University Chemical Laboratories, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
J Chem Theory Comput. 2014 Dec 9;10(12):5599-5605. doi: 10.1021/ct500797a. Epub 2014 Nov 4.
Effective parallel tempering simulations rely crucially on a properly chosen sequence of temperatures. While it is desirable to achieve a uniform exchange acceptance rate across neighboring replicas, finding a set of temperatures that achieves this end is often a difficult task, in particular for systems undergoing phase transitions. Here we present a method for determination of optimal replica spacings, which is based upon knowledge of local minima in the potential energy landscape. Working within the harmonic superposition approximation, we derive an analytic expression for the parallel tempering acceptance rate as a function of the replica temperatures. For a particular system and a given database of minima, we show how this expression can be used to determine optimal temperatures that achieve a desired uniform acceptance rate. We test our strategy for two atomic clusters that exhibit broken ergodicity, demonstrating that our method achieves uniform acceptance as well as significant efficiency gains.
有效的并行回火模拟关键依赖于精心选择的温度序列。虽然期望在相邻副本之间实现均匀的交换接受率，但找到一组能达到此目的的温度通常是一项艰巨的任务，特别是对于经历相变的系统。在此，我们提出一种基于势能景观中局部最小值知识来确定最优副本间距的方法。在谐波叠加近似的框架内，我们推导出并行回火接受率作为副本温度函数的解析表达式。对于特定系统和给定的最小值数据库，我们展示了如何使用此表达式来确定能实现所需均匀接受率的最优温度。我们对两个表现出遍历性破坏的原子团簇测试了我们的策略，证明我们的方法实现了均匀接受率并显著提高了效率。
