The structure and potential energy function of AlOH( C S ，X 1 A′)

By using MP4/6-311G(3df,3pd) method, the equilibrium geometry of AlOH molecule has been calculated .The possible electronic state and the reasonable dissociation limit for the ground state of AlOH ( C S ，X 1 A′) molecule is determined based on atomic and molecular reaction statics. The analytic potential energy function of AlOH molecule was derived by many-body expansion theory.