On the Perturbation—Variation Calculation of Spin—Spin Coupling Constants

Abstract
The use of the perturbation—variation method to calculate spin—spin coupling constants is examined. It is shown that the use of trial functions with δ‐function singularities leads to ambiguous results (this ambiguity is explicitly exhibited for HD). With the ambiguity removed a calculation of JHD is performed using correlated ground‐state and trial wavefunctions. It is concluded that convergence is slow.