MINDO/3 calculations of the geometrical structure of the Lewis acid site on (0001) α-Al2O3

• DOI: 10.1016/0039-6028(92)90533-c
• Publication Date: 2002-10-18T12:58:00Z
• Authors: N.N. Ilchenko; L.G. Gorb; V.V. Goncharuk
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract The relaxation of the Lewis acidic site (LAS) on the (0001) α-Al 2 O 3 face was studied by the semi-empirical SCF MO LCAO method within the MINDO/3 approximation with geometry optimization. The possibility of strong relaxation of the atoms was demonstrated. This rearrangement takes place due to the filling of vacant oxygen octahedra with coordinatively unsaturated Al atoms. The interaction of the LAS with a H 2 O molecule was studied. The calculation shows that the geometric parameters of the LAS change substantially due to the interaction with the H 2 O molecules. This process is accompanied with transfer of the LAS Al atoms from the structural coordination state with lattice oxygen atoms into the adsorption one.