AFLOW Integrated infrastructure for computational materials discovery MARCO

AFLOW: Integrated infrastructure for computational materials discovery MARCO ESTERS DAVID HICKS COREY OSES RICO FRIEDRICH CORMAC TOHER FRISCO ROSE S. CURTAROLO Materials Science Duke University

AFLOW School Team Marco Esters David Hicks Corey Oses Rico Friedrich Cormac Toher Stefano Curtarolo 2

Novel Materials Applications Biocompatible, corrosion resistant alloys: medical implants Photovoltaic materials: solar energy harvesting Thermal barrier coatings: energy/aerospace Superhard, wear resistant coatings: machine tools Superconductors and heat sinks for advanced electronics Solid state electrolyte: Li-ion batteries 3

Challenge: materials space 4

Challenge: materials space 177 10 M. J. Mehl et al. , Comput. Mater. Sci. 136, S 1 -S 828 (2017); D. Hicks et al. , Comput. Mater. Sci. 161, S 1 -S 1011 (2019) 5

Automated Materials Discovery • Automated computational materials discovery: Experimental structures Automated QM calculations Structural prototypes Density functional theory Searchable/sortable database Candidate materials http: //www. aflow. org ML models 6

AFLOW: Automatic FLOW AFLOW Input file generation aflow. in DFTCalculation management DFT-code AFLOW source code now available under GPL 3 materials. duke. edu/AFLOW/ Property calculation Database storage code Electronic DFTcode ERROR? Thermal Elastic Storage Curtarolo et al. , Comput. Mater. Sci. 58, 218 (2012); Calderon et al. , Comput. Mater. Sci. 108 A, 233 (2015) 7

AFLOW: Installation • AFLOW can be used on Linux, Mac, and Windows • Windows requires additional software: – Windows Subsystem for Linux (Windows 10) – Cygwin (other Windows versions) • For instructions and installation scripts, visit: http: //aflow. org/install-aflow/ Curtarolo et al. , Comput. Mater. Sci. 58, 218 (2012); Curtarolo et al. , Comput. Mater. Sci. 58, 227 (2012) 8

Outline • Session 1: Introduction, database, AFLUX (M. Esters) • Introduction to AFLOW • Database overview and search page • Database interfaces (AFLUX Search-API) • Session 2: Structure prototyping (D. Hicks) • Resolving material/structural prototypes • AFLOW crystal prototypes (encyclopedia) • AFLOW prototype generation • Session 3: AFLOW-CHULL (C. Oses) • • Identifying stable vs. unstable structures Defining minimum Gibbs free energy surface (convex polytope) Applications: Rare-earth free Heusler magnets AFLOW-CHULL web app 9

Outline • Session 4: AFLOW CCE (R. Friedrich) • Thermodynamic stability of polar materials • The coordination corrected enthalpies (CCE) method • AFLOW-CCE web app • Session 5: Machine Learning (C. Toher) • PLMF representation for electronic and thermomechanical properties prediction • AFLOW-ML Online • Concluding Remarks 10

AFLOW: Future Schools • Information on past and future AFLOW schools is available at: http: //aflow. org/aflow-school/ • School lengths can vary in length from half-day (this tutorial), full-day workshop, to multi-day school (e. g. 3 -day school recently hosted by Texas A&M) • Multi-day schools contain much additional information, particularly on running first-principles calculations using the AFLOW framework • To register interest in participating in or hosting future multi-day workshops, please contact Prof. Stefano Curtarolo: stefano@duke. edu 11

AFLOW. org: web portal aflow. org > 588 million properties > 3. 2 million entries breakdown of properties Curtarolo et al. , Comput. Mater. Sci. 58, 218 (2012); Calderon et al. , Comput. Mater. Sci. 108 A, 233 (2015) 12

AFLOW. org: applications aflow. org Curtarolo et al. , Comput. Mater. Sci. 58, 218 (2012); Calderon et al. , Comput. Mater. Sci. 108 A, 233 (2015) 13

AFLOW. org: search page Exercises: 1. Use the advanced search functionality to find the band gap for Si. C in the zincblende structure (space group number 216). 2. Use the advanced search functionality to find the bulk moduli for materials containing Ti in the AFLOW database. How many results are returned? 3. Use the “Restrict Value” button to limit the search to only entries for which the bulk modulus has already been calculated for materials containing Ti. Open the entry page of the material with the highest bulk modulus. What is the lattice type and space group of this material? Is it a metal or an insulator? Alternative aflow. org link: http: //aflowlib. duke. edu/search/ui R. H. Taylor et al. , Comput. Mater. Sci. 93, 178 -192 (2014) 16

AFLUX: AFLOW Search-API Logical operator LUX syntax <block> “(” and “)” <AND> “, ” <OR> “: ” <NOT> “!” <loose> “*” <string> “’” <mute> “$” • Aim: Programatically expose the same functionality as our web search interface at http: //aflow. org/search/advanced. php F. Rose et al. , Comput. Mater. Sci. 137, 362 (2017). 17

AFLUX: AFLOW Search-API • AFLUX enables search functionality through query part of URI • Supports use of several logical operators • Operator scope can be inter-property and/or intra-property Logical operator AFLUX syntax Operator scope <block> “(” and “)” Intra- and inter-property <AND> “, ” Intra- and inter-property <OR> “: ” Intra- and inter-property <NOT> “!” Intra-property <loose> “*” Intra-property <string> “’” Inter-property <mute> “$” Intra-property F. Rose et al. , Comput. Mater. Sci. 137, 362 (2017). 18

AFLUX: AFLOW Search-API http: //aflow. org/API/aflux/? <matchbook>, <directives> Search API Server Query • Matchbook: • Materials keywords with arguments • Example: <server>/? species((Na: K), Cl), nspecies(2), Egap(1*, *5), energy_cell • Keyword list available from schema directive: <server>/? schema • Directives: • Formatting instructions with arguments • “format” takes arguments “json” and “html” • “paging” controls number of entries and page displayed, sorted in ascending order of first materials keyword – order can be reversed by using a negative page number in the argument F. Rose et al. , Comput. Mater. Sci. 137, 362 (2017). 19

AFLUX: AFLOW Search-API Exercises: • Use AFLUX to retrieve the formation enthalpies for all entries in a ternary alloy system of your choice (keyword: enthalpy_formation_atom). • Use AFLUX to retrieve the space group numbers of all materials that contain Cu and Ti but not V (the logical NOT operator is denoted by the exclamation mark “!”; keyword: spacegroup_relax). • Use AFLUX to retrieve the band gaps of all of the materials that have a calculated bulk modulus between 200 GPa and 300 GPa (keyword: ael_bulk_modulus_vrh). • Use AFLUX to retrieve the materials that contain the element Sn but not Pb, and that have a band gap between 1 e. V and 3 e. V. How many such materials are available? R. H. Taylor et al. , Comput. Mater. Sci. 93, 178 -192 (2014) 20