Studies of the $M1\text{−}E2$ interference effect in the mixed-type forbidden lines 461.5, 647.6, and 875.5 nm of Bi I are reported. A special computer program considering the interference effect was designed to obtain the predicted contours of the Zeeman structures of the lines. By variation of free parameters describing the line shapes and the electric-quadrupole admixtures, the calculated profiles were fitted to the recorded spectra. The $E2$ admixtures found are $\left(7.84\pm 0.14\right)\%$, $\left(17.5\pm 0.4\right)\%$, and $\left(0.70\pm 0.11\right)\%$ for the 461.5, 647.6, and 875.5 nm lines, respectively. Our results are compared with recent theories and other experiments.

• Received 20 November 2007

DOI:https://doi.org/10.1103/PhysRevA.77.023410