Magnetic field effects on radical pair reactions: estimation ofB_1/2for flavin-tryptophan radical pairs in cryptochromes

Abstract

Magnetic field effects on the yields of radical pair reactions are often characterised by the “half-field” parameter, B1/2, which encodes useful information on spin relaxation, radical recombination kinetics and electron-electron...

Orientation of birds in radiofrequency fields in the absence of the Earth’s magnetic field: a possible test for the radical pair mechanism of magnetoreception

“…To simulate the effects of RF fields on the [FAD •− TrpH •+ ] radical pair, we used the stochastic Schrödinger equation method [42], implemented in the spin dynamics software MolSpin [43][44][45]. The initial nuclear spin space was trace-sampled using 96 SU(Z) coherent states [42] propagated using the short iterative Lanczos method [46,47] with time steps δt = 0.5 ns or 1 ns for a total time T of 5 or 7 μs. Equation (2.2) was used to obtain Φ S (θ) with an exponential extrapolation procedure to extend p S (t, θ) to t = ∞.…”

“…A total of 14 nuclear spins were included, 7 in each radical (electronic supplementary material, table S1). The dipolar coupling tensor, D, was calculated from the separation of FAD and Trp318 in the crystal structure of pigeon Cry4a [47,48]. Despite the name of the method, the calculations presented here were performed for monochromatic RF fields, with no stochastic terms in the spin Hamiltonian.…”