INVESTIGATION OF THE COMPOUND HF2NI - THE ELECTRONIC-STRUCTURE AND THE ELECTRIC-FIELD GRADIENT

The electronic structure and electric field gradient (EFG) of the inte rmetallic compound Hf2Ni are calculated on the basis of a recently dev eloped first-principles band-structure full-potential (FP) linear-muff in-tin-orbital (LMTO) scheme within the atomic sphere approximation (A SA). The calculated value of the EFG at the I-If sites is in very good agreement with the results obtained by the time-differential perturbe d angular correlation (TDPAC) technique used for the experimental stud y of the EFG at Ta-181 impurity sites in the compound Hf2Ni. The asymm etry parameter eta and the individual contributions to the EFG are dis cussed. It is shown that various treatments of 4f hafnium electrons ha ve a large influence on the EFG. The formulae for all of the component s of the EFG tensor (the contributions from the valence electrons as w ell as the lattice contribution) are derived and presented also.