We present a truncation scheme of the effective average action approach of
the nonperturbative renormalization group which allows for an accurate
description of the critical regime as well as of correlation functions at
finite momenta. The truncation is a natural modification of the standard
derivative expansion which includes both all local correlations and two-point
and four-point irreducible correlations to all orders in the derivatives. We
discuss schemes for both the symmetric and the symmetry broken phase of the
O(N) model and present results for D=3. All approximations are done directly in
the effective average action rather than in the flow equations of irreducible
vertices. The approach is numerically relatively easy to implement and yields
good results for all N both for the critical exponents as well as for the
momentum dependence of the two-point function.Comment: 6 pages, 1 figure, 3 table