Automorphisms of Chevalley groups of different types over commutative rings

AbstractIn this paper we prove that every automorphism of (elementary) adjoint Chevalley group with root system of rank >1 over a commutative ring (with 1/2 for the systems A2, F4, Bl, Cl; with 1/2 and 1/3 for the system G2) is standard, i.e., it is a composition of ring, inner, central and graph automorphisms