P. Gorski et al., CORRELATION BETWEEN IONICITY AND NONLINEAR REFRACTIVE-INDEX IN ALKALI-HALIDES, Physica status solidi. b, Basic research, 197(1), 1996, pp. 265-269
A relationship between the generalized Miller delta(1111)(omega; omega
, omega, omega) coefficient and the Phillips-van Vechten ionicity in a
lkali halides is presented. The correlation is employed to estimate th
e nonlinear refractive index of these crystals.