ADAIS: Automatic Derivation of Anisotropic Ideal Strength via high-throughput first-principles computations

Abstract

Anisotropic ideal strength is a fundamental and important plasticity parameter in scaling the intrinsic strength of strong crystalline materials, and is a potential descriptor in searching and designing novel hard/superhard materials. However, to the best of our knowledge, an automatic derivation of anisotropic ideal strength has not been implemented in any open-source code available so far. In this paper, we present our developed ADAIS code, an automatic derivation of anisotropic ideal strength via high-throughput first-principles computations for both three-dimensional and two-dimensional crystalline materials with any symmetry, as well as for an ideal interface model. Several fundamental mechanical quantities can be automatically derived, including ideal tensile and shear strengths through affine deformation, universal binding energy and generalized stacking fault energy, as well as the ideal cleavage and slide stresses through alias deformation. The implementation of this code has been comprehensively demonstrated and critically validated by a lot of evaluations and tests of various crystalline materials with different symmetry, indicating that our code could provide a high-efficiency solution to quantify the strength of strong solids. Program summaryProgram title: ADAISProgram Files doi:http://dx.doi.org/10.17632/336hry5g66.1Licensing provisions: BSD 3-ClauseProgramming language: Fortran90Nature of problem: A scheme adapted to high-throughput first-principles computations is much necessary to automatically determine the anisotropic ideal strength along any crystallographic orientation under affine and alias deformations for crystalline solids with any symmetry.Solution method: To derive the ideal strength of a crystalline solid along a specific crystallographic orientation, a projection and/or redefinition of a lattice are firstly performed. The affine (alias) deformation is then applied to the projected (redefined) lattice, and a relaxation is done on the distorted structure by the simply modified VASP code optimizer with certain cell constraints. Afterwards, the resultant total energies and stresses vs strain are generated accordingly. Finally, the anisotropic ideal strengths are derived from the calculated stress/energy–strain relationship, and meanwhile the variation of bond length as a function of strain is revealed to illustrate the failure mode. Whenever an unexpected error happens, a message will be printed for further evaluation.