EAPOT is an integrated software platform which is designed and organized by Dr. B. N. Yao and Prof. R. F. Zhang at Beihang University in recent five years to build empirical interatomic potential. It includes single component EAPOTs [Copyright No.: 2019sr0190574], multi-component EAPOTc [Copyright No.: 2019sr1395181] and verification system EACHK [Copyright No.: 2020sr0748849]. Through the convenient interactive interface, it can realize the choice of various potential function forms, the setting of fitting target parameters, the integration of various local and global optimization algorithms, and the verification and analysis window, so as to provide users with a whole process integration platform. The software platform not only realizes the high-throughput automatic fitting process based on first principles calculation, but also realizes the multiple combination and multi-level objective optimization scheme of "energy-stress-force-elasticity", which ensures that the fitting strategy can meet the needs of different simulation scenarios. Compared with other similar softwares such as potfit, meamfit, atomicrex, etc., this software exhibits a series of advantages, e.g. more concise control interface, richer function form, more powerful optimization algorithms, and higher integration degree.

Functionals

The default user interface for EAPOTs is shown below:

Graphical user interface of EAPOTs

EAPOTs is the first module used to construct and check the element potential. The supported potential functions include: Zhou's EAM multi-body potential function, Voter's EAM multi-body potential function, Mishin's EAM multi-body potential function, Finnis FS multi-body potential function, Ackland's FS multi-body potential function, Dai's FS multi-body potential function, Rosato's TB multi-body potential function, Li's TB multi-body potential function, SW three-body potential function, Tersoff’s and Brenner’s bond order potential function, the MEAM multi-body potential function of Baskes and the second-order MEAM multi-body potential function of Lee. EAPOTc is the second module of EAPOT, which is used for the construction and verification of multi-element cross potential. The supported cross functions for EAM, FS and TB potentials include those proposed by Morse, Johnson, Zhou, Demkowicz, Dai, Mishin, Ackland and cubic spline, as well as those cross parts for the SW 3-body potential, Tersoff and Brenner bond order potential, and MEAM multi-body potential. The two modules support the following fitting functions: model creation, energy fitting (coherent energy, vacancy energy, interstitial energy, stacking fault energy, surface energy, etc.), force fitting, stress fitting, modulus fitting, etc. Different fitting target selection can meet the demands of different simulation scenarios. The optimization algorithms of the two modules not only include local optimization algorithms, such as conjugate gradient method, simplex algorithm and Powell algorithm, but also support global optimization algorithms, such as particle swarm optimization, simulated annealing and differential evolution, as well as their combinations. The software platform can run on a single processor or multi task distribution. It is written in highly portable C + + language. It has high running efficiency and easy to expand new functions. It can be built into a library to call EAPOTs or EAPOTc through the library interface.

The EAPOT is currently copyrighted and distributed free of charge for academic, scientific, and educational, and non-commercial users with our permission. Commercial users may also use this software with no cost until a license is established, or with a contract for payment for the patent or technical support. This software is provided ‘as it is’ without any expressed or implied warranty. To obtain the EAPOT, one can send an email with the registration form to the email: zrfcms@buaa.edu.cn.

RegForm for EAPOT Studio.docx