Diabat Interpolation for Polymorph Free-Energy Differences

详细信息    查看全文

• 作者：Kartik KamatBaron Peters
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2017
• 出版时间：February 2, 2017
• 年：2017
• 卷：8
• 期：3
• 页码：655-660
• 全文大小：421K
• ISSN：1948-7185

文摘

Existing methods to compute free-energy differences between polymorphs use harmonic approximations, advanced non-Boltzmann bias sampling techniques, and/or multistage free-energy perturbations. This work demonstrates how Bennett’s diabat interpolation method (J. Comput. Phys.1976, 22, 245) can be combined with energy gaps from lattice-switch Monte Carlo techniques (Phys. Rev. E2000, 61, 906) to swiftly estimate polymorph free-energy differences. The new method requires only two unbiased molecular dynamics simulations, one for each polymorph. To illustrate the new method, we compute the free-energy difference between face-centered cubic and body-centered cubic polymorphs for a Gaussian core solid. We discuss the justification for parabolic models of the free-energy diabats and similarities to methods that have been used in studies of electron transfer.