TUNNELING CURRENTS IN ELECTRON-TRANSFER REACTION IN PROTEINS .2. CALCULATION OF ELECTRONIC SUPEREXCHANGE MATRIX ELEMENT AND TUNNELING CURRENTS USING NONORTHOGONAL BASIS-SETS
Aa. Stuchebrukhov, TUNNELING CURRENTS IN ELECTRON-TRANSFER REACTION IN PROTEINS .2. CALCULATION OF ELECTRONIC SUPEREXCHANGE MATRIX ELEMENT AND TUNNELING CURRENTS USING NONORTHOGONAL BASIS-SETS, The Journal of chemical physics, 105(24), 1996, pp. 10819-10829
In this paper we further develop the concept of interatomic tunneling
currents [A.A. Stuchebrukhov, J. Chem. Phys. 104, 8424 (1996)] for the
description of long-range electron tunneling in proteins. Here we dis
cuss a formulation of the theory for the case when nonorthogonality of
the atomic basis set of the medium propagating electron is explicitly
taken into account. This method provides an effective computational s
cheme for an exact, i.e., nonperturbative, evaluation (in one-electron
approximation) of the superexchange electron tunneling matrix element
, and allows one to determine which regions in the protein matrix are
important for the tunneling process. The theory is applied for calcula
tion of tunneling currents and the electronic matrix element in His126
-Ru-modified blue copper protein azurin from a recent experimental wor
k of Gray and co-workers. Analysis of interatomic currents reveals a n
ontrivial structure of the tunneling flow between donor and acceptor i
n the intervening protein medium in this system. (C) 1996 American Ins
titute of Physics.