******************************************************************************* ██████╗ ██╗ ██╗ █████╗ █████╗ ███████╗ ██╔═══╝ ██║ ██║██╔══██╗██╔══██╗██╔═════╝ ██║ ███████║███████║██║ ██║███████╗ ██║ ██╔══██║██╔══██║██║ ██║╚════██║ ╚██████╗██║ ██║██║ ██║╚█████╔╝███████║ ╚═════╝╚═╝ ╚═╝╚═╝ ╚═╝ ╚════╝ ╚══════╝ WELCOME TO CHAOS database Combinatorial High-throughput Analysis & Optimization for Synthesis COREY OSES Johns Hopkins University 2022 - 2025 ******************************************************************************* LATEST VERSION OF THE FILE: v1.0 ******************************************************************************* Welcome to **CHAOS** — the Combinatorial High-throughput Analysis & Optimization for Synthesis database, a comprehensive open-access platform designed to advance next-generation materials discovery. Spanning metals, intermetallics, ceramics, semiconductors, catalysts, and energy-relevant compounds, CHAOS provides rigorously validated thermodynamic, structural, electronic, mechanical, and functional properties with standardized and fully machine-actionable data. *************** CHAOS search API Instruction *************** **Base URL** https://s4e.ai/API/chaos/? All queries (called ) are written directly after the ‘?’ No extra path, no slashes Example: https://s4e.ai/API/chaos/? **Quick examples** - This help page: https://s4e.ai/API/chaos/?help - Schema: https://s4e.ai/API/chaos/?schema - Cell potential ≥ -25 eV/cell: https://s4e.ai/API/chaos/?energy_cell(-25*) ### Query Structure Every query consists of two logical parts: | Part | Purpose | |------------|----------------------------------------------------------------| | Matchbook | What to search for & which properties to return/filter | | Directives | How the output is formatted and delivered | ### Quick Access | What you want | Query example | |----------------------------------|------------------------| | This help page | help | | Full list of all properties | schema | | Details on one property | help(energy_cell) | | All aliases | help(aliases) | | All directives | help(directives) | ### Logic Operators Cheat Sheet | Symbol | Meaning | Example | |--------|----------------------------------|--------------------------------------| | N* | ≥ N | energy_cell(-20*) | | *N | ≤ N | energy_cell(*-20) | | , | AND | density(3*),species(O) | | : | OR | density((1*,*2):(3*,*4)) | | ! | NOT | species(!H) | | $ | Suppress default fields | $compound,$aurl | | @ | Tensor / species-specific filter | ael_compliance_tensor(@(3,3)(0*)) | ### Chaos API – Query Syntax & Directives ### 1. Basic Numerical Queries | Goal | Query example | |------------------------------------------------|------------------------------------------| | Entries that have cell potential | energy_cell(*) | | Cell potential ≥ -40.0 and ≤ -20.01 eV/cell | energy_cell(1*,*1.01) | | Multiple OR range | density((1*,*1.01):(2*,*2.01)),paging(2) | | Second page (64 entries per page) | density(3*),paging(2) | ### 2. Pagination | Goal | Query example | |-----------------------------------|-------------------| | Page 3 (default size 64) | paging(3) | | All results (no pagination) | paging(0) | | Page J with custom size K | paging(J,K) | **Important note** `paging(0)` / `paging(-0)`** returns all possible results. Large data responses can crash your browser. Prefer using `wget`, `curl`, or any other direct download tool for full retrieval. ### 3. String Matching | Goal | Query example | |-------------------------------|------------------------------------| | Contains “28” | Pearson_symbol_relax(*'28'*) | | Does NOT contain “F” | Pearson_symbol_relax(!*'F'*) | Browser percent-encoding is handled automatically. Don't worry about browser percent-encoding, CHAOS API will still handle automatically. ### 4. Multiple Properties & Suppression | Goal | Query example | |-------------------------------------------|---------------------------------------------------| | Density + Pearson symbol (all results) | density(6*,*7.51),Pearson_symbol_relax,paging(-0) | | Same but hide compound name | density(1*,*1.01),Pearson_symbol_relax,$compound | ### 5. Inversion | Goal | Query example | |-------------------------------------------|---------------------------------------| | No “F” in Pearson symbol (all results) | Pearson_symbol_relax(!*'F'*),paging(0)| | Cell potential strictly > -10 eV/cell | energy_cell(!*-10) | ### 6. Tensors & Species-Specific Filters | Goal | Query example | |---------------------------------------------------|-----------------------------------------| | Stress tensor: first diagonal element ≥ 0 | stress_tensor(@(0)(0*)) | | Elastic compliance tensor: element (1,1) ≤ 0 | ael_compliance_tensor(@(1,1)(0*)) | | Any chlorine atom has net charge ≤ 0 | bader_net_charges(@Cl(*0)) | | Any iron atom positively charged OR any oxygen ≤ 0| bader_net_charges(@Fe(0*):@O(*0)) | ### 7. Popular Aliases | Goal | Query example | |-----------------------|---------------------------| | Any alkali metal | species(AlkaliMetals) | | Any transition metal | species(TransitionMetals) | | Any lanthanide | species(Lanthanides) | | Any halogen | species(Halogens) | | Any chalcogen | species(Chalcogens) | ### 8. Popular Directives | Directive | Effect | |-----------|---------------------------------------| | format | Output format: json or html | | paging | Controls pagination | | catalog | Filters by database subset | *************** Contribution Guidelines *************** To contribute data or expand the database, generate entries using aflow++ (open-source at https://github.com/entropy4energy/AFLOW-src) and submit via S4E Laboratory (contact corey.oses@jhu.edu). Suggestions for new descriptors or structures welcome. Team: Jiayue Hu, Shao-Yu Tseng, Matthew Brownrigg, Guangshuai Han, Tianhao Li, William Shiber, Xiao Xu, Maya Niyogi, Keith Clark, Corey Oses (PI, Department of Materials Science and Engineering, Johns Hopkins University). *************** References & License *************** **References** CHAOS: Submitted (2025) aflow.org: https://doi.org/10.1016/j.commatsci.2022.111808 AFLUX: https://doi.org/10.1016/j.commatsci.2017.04.036 AFLOW REST API: https://doi.org/10.1016/j.commatsci.2014.05.014 **License** Data are free for **scientific, academic, and non-commercial use only**. Commercial use requires explicit permission from JHU S4E Group. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . **************** Enjoy the Chaos! ****************