A portable and flexible implementation of the Wang–Landau algorithm in order to determine the density of states

In this work we develop an implementation of the Wang–Landau algorithm Wang and Landau (2001) [4]arXiv e-prints. This algorithm allows us to find the density of states (DOS), a function that, for a given system, describes the proportion of states that have a certain energy. The implementation uses the Python and C++ languages for the algorithm itself, and it can take advantage of any library, such as the powerful LAMMPS library, for the computation of energy. Therefore, the resulting implementation is simple and flexible without sacrificing efficiency. This implementation also considers recent developments in the parallelization of the code for faster computation. We establish the soundness and effectiveness of our implementation by studying well-known systems such as the Ising model, the Lennard–Jones and EAM solids. We have found that our implementation can find the DOS with very good precision in a reasonable amount of time. Therefore, we are equipped with a very powerful and flexible implementation that can be easily used in order to study more realistic models of matter.

本研究针对Wang与Landau（2001）[4]发表于arXiv预印本的王-朗道（Wang–Landau）算法开发了一款实现方案。该算法可用于求解态密度（density of states, DOS）——这是一类用于描述给定系统中具有特定能量的态的占比的函数。本实现针对算法本体采用Python与C++语言开发，且可借助任意现有库完成能量计算，例如功能强大的LAMMPS库。因此，最终得到的实现方案兼具简洁性与灵活性，且未牺牲计算效率。本实现还兼顾了当前代码并行化领域的最新进展，以实现更快的计算速度。我们通过研究伊辛模型、伦纳德-琼斯固体以及嵌入原子法（Embedded Atom Method, EAM）固体等经典系统，验证了本实现的可靠性与有效性。实验结果表明，本实现可在合理的时间范围内以极高精度求得态密度。综上，我们得到了一款兼具强大性能与灵活性的实现方案，可便捷地用于研究更具现实意义的物质模型。