We present a new grid of LTE model atmospheres for weakly magnetic (B<~10^10^G) neutron stars, using X opacity and equation of state data from the OPAL project and employing a fully frequency- and angle-dependent radiation transfer. Model spectra for low-field neutron stars with three different photospheric compositions are presented: (1) pure hydrogen atmospheres, (2) atmospheres with solar abundances, and (3) pure iron atmospheres. Each grid covers 29 effective temperatures log(Teff[K])=5.10-6.50 in steps of 0.05. The model spectra are tabulated as angle-averaged unredshifted (surface) Eddington fluxes. All spectra have been calculated for a canonical neutron star configuration, M_ns_=1.4M_{sun}, R_ns=10km, corresponding to a surface gravitational acceleration of log(g)=14.386. The same model grids are also available as XSPEC tables at http://legacy.gsfc.nasa.gov/docs/xanadu/xspec/models/gbr.html