An improved decoupling approximation is proposed to estimate the spati
al average of \E\(beta), where \E\ denotes the magnitude of the local
electric field E and beta (beta greater than or equal to 3) is the non
linear exponent. As an example, we recalculate the nonlinear susceptib
ilities of weakly nonlinear composites and find that our present resul
ts are very close to the simulation data. (C) 1998 Elsevier Science B.
V.