Complex

Complex commonly refers to:


 * Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe
 * Complex system, a system composed of many components which may interact with each other
 * Complex (psychology), a core pattern of emotions etc. in the personal unconscious organized around a common theme such as power or status

Complex may also refer to:

Arts, entertainment and media

 * Complex (English band), formed in 1968, and their 1971 album Complex
 * Complex (band), a Japanese rock band
 * Complex (album), by Montaigne, 2019, and its title track
 * Complex (EP), by Rifle Sport, 1985
 * "Complex" (song), by Gary Numan, 1979
 * "Complex", a song by Katie Gregson-MacLeod, 2022
 * "Complex" a song by Be'O and Zico, 2022
 * Complex Networks, publisher of the now-only-online magazine Complex

Biology

 * Protein–ligand complex, a complex of a protein bound with a ligand
 * Exosome complex, a multi-protein intracellular complex
 * Protein complex, a group of two or more associated polypeptide chains
 * Species complex, a cluster of very similar species difficult to delimit
 * Pre-Bötzinger complex, a cluster of interneurons in the ventral respiratory group of the medulla of the brainstem

Chemistry

 * Coordination complex, a central atom or ion and a surrounding array of bound molecules or ions
 * Chelate complex, a coordination complex with more than one bond

Mathematics

 * Complex number, an extension of real numbers obtained by adjoining imaginary numbers
 * Complex polytope, a generalization of a polytope in a complex Hilbert space
 * Complex analysis, the study of functions of complex numbers
 * Complex, an element of a field of sets
 * Chain complex, an algebraic structure
 * Simplicial complex, a kind of topological space
 * CW complex, a kind of topological space
 * Line complex, a 3-dimensional family of lines in space

Geology

 * Complex (geology), a unit of rocks composed of rocks of two or three types
 * Complex crater, a type of large impact crater morphology
 * Volcanic complex, a group of volcanoes
 * Complex volcano, a volcano of mixed form
 * Accretionary complex, a fossil accretionary wedge

Other uses

 * Building complex, a group of inter-related buildings
 * Housing complex, specifically residential
 * Market complex, group of stores or business firms in a marketplace having common walkway(s), usually enclosed within a boundary or situated under one roof
 * UCL Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), part of UCL Faculty of Mathematical and Physical Sciences, London, UK