Calculation of the deuterium electric field gradient in DF.

We report theoretical results of the electric field gradient at the position of the deuterium nucleus in the DF molecule. The purpose of the calculation is the evaluation of a correction term to the expectation value of the electric field gradient with respect to a linear combination of atomic orbitals-molecular orbital self-consistent field (LCAO-MO SCF) function proposed by Ransil. Our method is based on a variation-perturbation method that was proposed previously. The expectation value of q0D (el) is qD =-2.8964, the corrected value is qD (el)=-2.9056, and the experimental value is qD (exp)=-2.9241 (all values are expressed in terms of atomic units). The difference between our theoretical value and the experimental result is 0.6%. [ABSTRACT FROM AUTHOR]