Abstract
The position of the (F, MF)=(1, 0)(1, 1) transition in the P122 level of atomic fluorine has been accurately measured and a g factor calculated. The result is gJ(F; P122)=0.6656117±0.0000021. This result is in excellent agreement with the previously published value of 0.665 61 ± 0.000 03, but differs by 25 parts per million from a recent calculation carried out to order α2 in relativistic contributions according to the theory of Kambe and Van Vleck. The result is discussed in terms of the theories of Abragam and Van Vleck, and Kambe and Van Vleck.