Density functional study of magnetic coupling parameters: F and H hyperfine splitting constants for the prototype inorganic (d(1)) and organic (p(1))radicals TiF3 and CH3

Hyperfine splittings (hfs) are calculated for the title compounds. These ca lculations resolve the discrepancy found earlier(1) between the calculated and experimental hfs for F in TiF3 by (a) cartful consideration of the spin polarization effects in the occupied 2s and 2p shells, as well as the nonn egligible spin polarization of the Is shell, and (b) reconsideration of the experimental results by redefining the relative signs of the principal val ues of the A tensor on the basis of the calculations. The presently availab le density functionals (LDA, GGA's) are shown to yield fair agreement for t he magnetic coupling parameters, indicating the usefulness of the DFT calcu lations for interpretation of ESR data of large complexes. Such interpretat ion is difficult on the basis of the experimental hfs data only, due to the intricacies of the spin polarization mechanism that gives rise to them.