SYSTEMATIC STUDIES OF THE 2S(2) S-1(0)-2S3P P-1(1)0 TRANSITION IN THEBE-LIKE SEQUENCE

Results from systematic multiconfiguration Hartree-Fock studies of the 2s(2) (1)S2s3p(1)P(o) transition in the Be-like sequence in the range of Z = 4-10 are reported for several models. The inclusion of core-va lence correlation is essential for obtaining good agreement in the len gth and velocity form of the oscillator strength, the agreement improv ing with Z and reaching one part in 4000 for neon. in the case of Be, extensive cancellation occurs in the calculation of the dipole matrix element and correlation in the 1s(2) core already plays a role at the 1% level of accuracy. The orbitals obtained from the core correlation model were used in a Breit-Pauli calculation mixing P-1,3(o) states. T he effect on the allowed transition data is included. The present calc ulations are generally in better agreement with semi-empirical values predicted from experiment than from experiment itself.