Electronic decoherence for electron transfer in blue copper proteins

We present a molecular dynamics investigation of the electronic decoherence rate for electron transfer (ET) in a solvated protein molecule. We find th at decoherence occurs on an ultrafast time scale of 2.4 fs, considerably fa ster than fluctuations in the electronic coupling. Both protein and solvent dynamics play important roles. Solvent alone would give rise to a decohere nce time of 3.0 fs, as compared to 4.1 fs from the protein matrix alone. Th is implies that both solvation and protein dynamics can strongly affect bot h the rate and mechanism of ET. (C) 2001 Elsevier Science B.V. All rights r eserved.