The effect of hydrostatic pressure and temperature on the local molecular structure for Mn2+ ions in the Zn(BF4)(2)center dot 6H(2)O:Mn2+ sys- tern have been investigated by diagonalizing the complete energy matrices for a d(5) configuration ion in a trigonal ligand-field. By simulating the EPR parameters D and (a - F), the local lattice structure parameters R and theta under different conditions have been determined. The results show that the local lattice structure of the [Mn(H2O)(6)](2+) octahedron has a compressed distortion with increasing the pressure, and a elongated distortion with the temperature rising. Moreover, the electronic transition energies for Mn 2+ ions in the Zn(BF4)(2)center dot 6H(2)O crystal at 293 K are reported for the first time. (c) 2007 Elsevier B.V. All rights reserved.