Change of the conversion rate of the E 3 isomer /sup 235m/U (76.8 eV; (1)/(2) +→ (7)/(2) -) upon variation of the configuration of the valence band of the atomic shell

The relativistic Hartree-Fock-Slater method is used to calculate the change of the conversion rate lambda for the E3 isomer (at the transition energy hω = 77 eV) relative to the value lambda1 for the normal atomic configuration (7s (1)/(2) )2(6d (3)/(2) )1(5f (5)/(2) )3 for 14 configurations of the valence band of the atomic shell of uranium including significant variations of the occupation numbers of the 6d, 7s, and 5f orbits. A very strong change Δlambda/lambda1 is found to occur upon variation of the occupation number of the 5f orbit [ΔN(5f)not =0], namely, approx.8% for ΔN(5f) = +- 1, which is an order of magnitude greater than the value of Δlambda/lambda1 due to the variation of the occupation numbers of other orbits with N(5f) = const. In spite of the fact that the direct contribution of 5f electrons to the conversion is very small (< or approx. =0.1%), a variation ΔN(5f) of the occupation number of the well-localized 5f orbit leads to the same change of the screening for the more extended 6p and 6d orbits, which are mainly responsible for the conversion. This cophased effect produces a strong total change Δlambda/lambda1 for ΔN(5f)not =0. A rigid correlation between the partial conversion rate and the rms radius of the orbit is established for 6p orbits