The E2 admixtures in mixed multipole lines 459.7 and 564.0 nm of Bi IThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at University of Windsor, Windsor, Ontario, Canada on 21–26 July 2008.

Studies of the M1-E2 interference effect in the Zeeman spectra of forbidden lines 459.7 and 564.0 nm of Bi I are reported. By the use of computer modelling techniques, the simulated contours were fitted to the recorded spectra to determine the electric-quadrupole admixture in forbidden lines. The E2 admixtures found are: (3.49 ± 0.35)% and (37.1 ± 1.8)% for 459.7 and 564.0 nm lines, respectively. Our results are compared with recent theories and other experiments.