QUASIRECOGNITION BY PRIME GRAPH OF FINITE SIMPLE GROUPS {}^2D_n(3)

Let G be a nite group. In [Ghasemabadi et al., characterizations of the simple group 2Dn(3) by prime graph and spectrum, Monatsh Math., 2011] it is proved that if n is odd, then 2Dn(3) is recognizable by prime graph and also by element orders. In this paper we prove that if n is even, then D = 2Dn(3) is quasirecognizable by prime graph, i.e. every nite group G with ??(G) = ??(D) has a unique nonabelian composition factor and this factor is isomorphic to D.