{"term":{"id":"02535","title":"front surface geometry","longtitle":"IUPAC Gold Book - front surface geometry","doi":"10.1351\/goldbook.F02535","code":"F02535","status":"current","definitions":[{"id":1,"text":"A system where excitation and observation are from the same face of the sample (\\(\\alpha\\ \\angle\\ 90^{\\,\\unicode{x26ac}}\\), \\(\\beta\\ \\angle\\ 180^{\\,\\unicode{x26ac}}\\) where \\(\\alpha \\) = angle of incidence of the exciting beam on the plane surface of the sample, and \\(\\beta \\) = angle between the exciting direction and observation direction.)","contexts":[],"links":[{"term":"angle","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/A00346"}],"sources":["PAC, 1984, 56, 231. 'Nomenclature, symbols, units and their usage in spectrochemical analysis-Part VI: molecular luminescence spectroscopy' on page 244 (https:\/\/doi.org\/10.1351\/pac198456020231)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/F02535\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/F02535\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/F02535\/plain"},"citation":"Citation: 'front surface geometry' 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.F02535","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":"2026-06-20T19:05:37+00:00"}}