  We present the results of 3D, high-resolution calculations of neutron star
mergers. Using Newtonian gravity, but adding the forces from the emission of
gravitational waves, we solve the hydrodynamics equations using the smoothed
particle hydrodynamics method. The microscopic properties of the neutron star
matter are described in terms of a new nuclear equation of state (EOS) based on
the tables of Shen et al. (1998). The effects of neutrino emission of all
flavours are accounted for. The new EOS is noticeably stiffer than the
Lattimer-Swesty-EOS used in previous investigations. We find in general
somewhat lower temperatures than previous investigations. This allows a
substantial fraction of heavy nuclei to be present even in the inner parts of
the torus that forms around the central object and yields important
contributions to the neutrino opacity. The central object shows a rapid
differential rotation with periods of $\sim$ 2ms, which we suspect to stabilize
the central object on (at least) the simulation time scale against
gravitational collapse. The differential rotation could wind up initial
magnetic fields to $\sim 10^17$ G.
