Petrie, SimonStranger, RobertPace, Ronald2015-12-100947-6539http://hdl.handle.net/1885/60975Density functional theory calculations are reported on a set of three model structures of the Mn4Ca cluster in the water-oxidizing complex of Photosystem II (PSII), which share the structural formula [CaMn 4C9H10N2O16] q+•(H2O)n (q=-1, 0, 1, 2, 3; n=0-7Keywords: Density-functional calculations; Metallo-proteins; Mixed-valent compounds; Photosystem II; water chemistry; Atoms; Binding energy; Biochemistry; Calcium; Crystal atomic structure; Density functional theory; Earthquake resistance; Enzymes; Hydration; Hydro density functional calculations; metalloproteins; mixed-valent compounds; photosystem II; water chemistry201010.1002/chem.2010011322016-02-24