Fig. 3.

Reaction yields of radical pairs with spin relaxation included. (A) The toy radical pair, [X^• Y^•]. X^• has a single ¹⁴N nucleus with hyperfine components (A_xx, A_yy, A_zz) = (−0.2, −0.2, 1.7569) mT; Y^• has a single ¹⁴N nucleus with hyperfine components (0.0, 0.0, 1.0812) mT. The two hyperfine tensors have parallel z axes. The radical pair lifetime is 10 μs. X^• underwent 10° rotational jumps (i.e., β = 5°) around the y axis with rate constants k_r between 3 × 10¹¹ and 10⁸ s⁻¹, as indicated. (B) The [FAD^•− Y^•] radical pair. FAD^•− has seven magnetic nuclei, as in Fig. 1. Y^• has single ¹⁴N nucleus with hyperfine components (A_xx, A_yy, A_zz) = (0.0, 0.0, 1.0812) mT. The radical pair lifetime is 10 μs. FAD^•− underwent 10° rotational jumps (i.e., β = 5°) around the y axis, with rate constants k_r varying between 3 × 10¹¹ and 10⁹ s⁻¹, as indicated. In A and B, the direction of the magnetic field (θ) is varied in the zx plane of the flavin ring system (Fig. 1A). Almost identical results were found for the zy plane.