Hyperfine interactions in the J = 5 states of 147Sm and 149Sm

The hyperfine interaction constants Ak(5) have been measured in 147Sm and 149Sm. Consideration of the k = 2 results together with Woodgate's values of A2(J) for J = 1 to 4 shows that his nonrelativistic treatment of the electric quadrupole interaction in samarium is inadequate but that a relativistic one gives excellent agreement. The effect cannot be confused with a possible configuration interaction as it can in the case of the magnetic dipole interaction. Allowance for the effects of octupolelike second-order corrections and more precise computation of the dipole- and quadrupole-like corrections markedly affect the published results for the hyperfine constants in the lower J states, but the revision does not improve the agreement with the theoretical expressions. It would appear that Conway and Wybourne's analysis of the breakdown of L–S coupling in the nominally 7F ground term is not adequate, particularly for the computation of the coefficient of the sC2 term.