Comparison of Two Efficient Methods for Calculating Partition Functions

• Main Authors: Le-Cheng Gong, Bo-Yuan Ning, Tsu-Chien Weng, Xi-Jing Ning
• Format: Article
• Language: English
• Published: MDPI AG 2019-10-01
• Series: Entropy
• Subjects: partition function; statistical physics; molecular dynamics simulations
• Online Access: https://www.mdpi.com/1099-4300/21/11/1050

In the long-time pursuit of the solution to calculating the partition function (or free energy) of condensed matter, Monte-Carlo-based nested sampling should be the state-of-the-art method, and very recently, we established a direct integral approach that works at least four orders faster. In present work, the above two methods were applied to solid argon at temperatures up to 300 K. The derived internal energy and pressure were compared with the molecular dynamics simulation as well as experimental measurements, showing that the calculation precision of our approach is about 10 times higher than that of the nested sampling method.