EN
The dependence of the crystal-field splitting parameter D in NiSnCl_6·6H_2O on hydrostatic pressure was determined by the electron paramagnetic resonance method, for the pressures up to 500 MPa. The derivative (∂D/∂p)_T as well as the temperatures and pressures at which the D-parameter reaches zero, were determined. The molecular mechanism responsible for the temperature and pressure changes of the D-parameter is similar to that one observed in the isomorphic NiSiF_6·6H_2O.