The AFLOW standard for high-throughput materials science calculations

Abstract

The Automatic-Flow (AFLOW) standard for the high-throughput construction of materials science electronic structure databases is described. Electronic structure calculations of solid state materials depend on a large number of parameters which must be understood by researchers, and must be reported by originators to ensure reproducibility and enable collaborative database expansion. We therefore describe standard parameter values for k-point grid density, basis set plane wave kinetic energy cut-off, exchange-correlation functionals, pseudopotentials, DFT+U parameters, and convergence criteria used in AFLOW calculations.

An efficient and accurate framework for calculating lattice thermal conductivity of solids: AFLOW—AAPL Automatic Anharmonic Phonon Library

“…All structures are fully relaxed using the automated framework AFLOW [28][29][30][31][32][33][34][35][36][37][38][39] and the VASP package. 113 Optimizations are performed following the AFLOW standards.…”

“…113 Optimizations are performed following the AFLOW standards. 34 The PAW potentials 114 are used and the exchange and correlation functionals parameterized by the generalized gradient approximation proposed by Perdew-Burke-Ernzerhof (PBE). 115 All calculations use a high-energy cut-off, which is 40% larger than the maximum recommended cut-off among all component potentials, and a k-point mesh of 8000 k-points per reciprocal atom.…”

“…For a rational software for accelerated materials development, all the geometric optimizations, symmetry analyses, supercell creation, pre-processing and post-processing, and automatic error corrections to get the IFCs, in addition to the appropriate integration for the BTE must be performed by a single code. Here, we present Automatic Anharmonic Phonon Library (AAPL), which computes the IFCs and solves the BTE to predict κ ' as part of the AFLOW high-throughput framework, [28][29][30][31][32][33][34][35][36][37][38][39] automatizing the entire process. The software is being finalized for an official open-source release during 2017, within the GNU GPL license.…”

Charge compensation and electrostatic transferability in three entropy-stabilized oxides: Results from density functional theory calculations

“…the localized 3d electrons in the row four elements, the orbital-dependent, Coulomb potential was included in the calculations using the DFTþ Hubbard U formalism in the simplified, rotationally invariant approach introduced by Dudarev et al 29 The U values used were 2.9, 5, 5.1, 4.5, and 7.5 for Sc, Co, Ni, Cu, and Zn, respectively. 30 A cut-off energy for the plane wave basis was set to 560 eV, and convergence was assumed when the energy difference between two consecutive self-consistent cycles was less than 10 À4 eV. For small binary and mixed oxide systems (8 atoms/cell, NaCl structure), the Brillouin-zone was sampled by a C-centered, 16 Â 16 Â 16 k-mesh, while only the C point was used for the larger cells.…”

Fermionic correlations as metric distances: A useful tool for materials science

“…For example, our results suggest that among the available approximations for the system-averaged exchange-hole, the meta-GGA performs best and could be used in evaluating distances for systems widely different in size and level of inhomogeneity. Our x-hole metric could also help guiding high-throughput materials design [22], e.g., for searching in large configurational spaces or for validating the reproducibility of a collaborative database of electronic calculations, independently from the different methodology, quantum package, or hardware used [23]. Natural metrics such as this or the one for the particle density [4] might also be used to ensure that newly developed functionals optimize, together with the total energies, other key physical quantities, helping revert the trend recently described in [24].…”