On -: K2 for normal surface singularities

In this paper we show the lower bound of the set of non-aero -K-2 for normal surface singularities establishing that this set has no accumulation points from above. We also prove that every accumulation point from below is a rational number and every positive integer is an accumulation point. Every rational number can be an accumulation point module Z. We determine all accumulation points in [0, 1]. If we fix the value -K-2, then the values of p(g), p(a), mult, embdim and the numerical indices are bounded, while the numbers of the exceptional curves are not bounded.