Effect of hydrostatic pressure in NQR spectra of α-HIO3 crystal

Intermolecular hydrogen bonds effecting symmetry and dynamics of intracrystal field in the α-HIO3 crystal has been considered. Baric and temperature dependences of principal values of constants of quadrupole interaction and assymmetry parameter of tensor of electric field gradient (EFG) on 127I resonant nucleus in the α-HIO3 crystal in the ranges of 4.2-300 K and 0-5 kbar, accordingly have been investigated to solve this problem. It is shown on the basis of performed calculations of electron structure of HIO3 molecule in the α-HIO3 crystal that peculiarities of symmetry and dynamics of intracrystal field resulted from the existence of hydrogen intermolecular bonds in the crystal. It is also shown when comparing values of baric and temperature coefficients of basic components of EFG-tensor and values of EFG-tensor asymmetry parameter with values obtained from the calculations of HIO3 molecule electron structure, that main effect of hydrostatic pressure due to the reduction of length of hydrogen intermolecular and increase of length of covalent O-H bond