{"term":{"id":"11409","title":"basis set superposition error","longtitle":"IUPAC Gold Book - basis set superposition error","doi":"10.1351\/goldbook.11409","code":"11409","status":"current","initialism":"<em>initialism<\/em>: BSSE","definitions":[{"id":1,"text":"An artifactual increase in calculated stability of the supersystem (the system formed by noncovalent interaction between two or more molecular entities, e.g. hydrogen bond system) resulting from the basis set of the supersystem being larger than for the component subsystems. The BSSE arises from a lowering of the quantum mechanical energy when the electron density of each subsystem spreads into the basis functions provided by the other subsystems.","sources":["PAC, 2016, 88, 239. 'Glossary of terms used in computational drug design, part II (IUPAC Recommendations 2015)' on page 241 (https:\/\/doi.org\/10.1515\/pac-2012-1204)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/11409\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/11409\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/11409\/plain"},"citation":"Citation: 'basis set superposition error' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.11409","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2026-07-13T01:41:06+00:00"}}