The experimental data carried out by Mossbauer and magnetic resonances inve
stigations of the structural phase transitions in K2ZnCl4 crystals are disc
ussed by a simple electrostatic model, calculating, the lattice contributio
ns to the local electric potential V(r), electric field intensity E(r) a,nd
electric field gradient tensor, V-alpha beta(r) and taking into account bo
th the fractional electric point charges and rigid lattice approximations.
The validity of the model is proved by a good fit of the computing results
and experimental data of quadrupole splitting parameters at K Bites obtaine
d by K-39-NMR methods in high temperature incommensurate phase (similar to
Pnam symmetry). The experimental results obtained by Mossbauer and EPR meth
ods in commensurate phase (Pna2(1) symmetry) of iron and copper doped K2ZnC
l4 crystals are explained by relaxing the rigid lattice approximation. The
insertion of probe ions appear to be done on not-exactly-Zn2+ site.