Term: crystal photochemistry https://doi.org/10.1351/goldbook.CT07350 Definition: Photochemical process in the crystal lattice of a photoactive compound or of a chromophore in the crystal lattice of host molecules. Often asymmetric photochemistry takes place. Related Terms: 1) chromophore (http://doi.org/10.1351/goldbook.C01076). 2) asymmetric photochemistry (http://doi.org/10.1351/goldbook.AT07328). Source: PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 319 (https://doi.org/10.1351/pac200779030293) Citation: 'crystal photochemistry' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.CT07350 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. 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.