1. The square of the matrix amplitude for the transition is [cf. Sugiura, loc. cit. equation (4)] multiplied by an absolute constant and by a factor depending on lA and lB , arising from the dependence of the wave functions on direction of the radius r. The factor v 4 arises from the relation between doublet amplitude and intensity of emitted radiation.
2. Dashes denote differentiation with respect to r.
3. Op. cit. § 16·12.
4. See Whittaker E. T. and Watson G. N. , Modern Analysis, ch. 16.