The EPR zero-field splitting of Mn-2(+) ions doped in single crystals of zinc fluoride hexahydrate series is studied by diagonalizing the complete energy matrices for d(5) configuration ions in a trigonal ligand field. By simulating the EPR parameters D and (a - F) simultaneously, the local structure parameters R = 2.252 angstrom, theta = 52.6006 degrees for ZnTiF6 6H(2)O:Mn2+, R = 2.266 angstrom, theta = 52.5466 degrees for ZnGeF6 6H(2)O:Mn2+, and R = 2.226 angstrom, theta = 52.9195 degrees for ZnNbOF5 6H(2)O:Mn2+ are determined, respectively, in which R is the Mn-O bond length and theta is the angle between the Mn-O bond length and C-3 axis. From our calculations, it is found that when Mn2+ doped in the isomorphous crystals there have a similar local distortion. (c) 2007 Elsevier B.V. All rights reserved.