Biomedical Engineering Reference
In-Depth Information
where is the TT exchange integral. The Hamiltonian of the exchange interaction (HSE)
between spins with operators
and
is described by the equation
where
is the SE exchange integral.
All three integrals and are related to the overlap integral which
quantitatively characterizes the degree of overlap of orbitals involved in these processes.
Thus
where is the distance between the interacting centers and is a coefficient which
characterizes the degree of the integral decay. In the first approximation n = 2 for the ET
and SE processes with the overlap of two orbitals and n = 4 for the TT process in which
four orbitals overlap (of ground and triplet states of the donor and ground and triplet states
of the acceptor). The spin exchange and TT phenomena may be considered an idealized
model of ET without or with only a slight) replacement of the nuclear frame. Thus, the
experimental dependence of exchange parameters
and
on the distance between the
Search WWH ::
Custom Search