Abstrait

Hartree-Fock ab Initio Study Of The Electronic Structure Of Perovskite (LaNiO3)

J.C.Pinheiro, M.S.Farias, F.A.M.de Lira, M.A.B.dos Santos, M.S.Lobato,A.F.de Figueiredo, J.P.Barbosa, J.E.V.Ferreira, E.B.Costa, R.D.P.Ferreira, O.Treu Filho, R.T.Kondo

In a previous paper [J.Mol.Struct.(Theochem) 671, 71, 2004] we reported a theoretical study effect in BaTiO3. In this report we studied of the electronic structure of the lanthanum niquelate (LaNiO3) to investigate the piezoelectricity in this material. In the calculations we used the 20s14p/5s3p and 31s23p18d/17s11p7d gaussian basis sets for the O (3P) and La (2D) atoms, respectively, from literature in combination with the 30s19p13d/11s8p6d basis set for the Ni (5D) atom, obtained by generator coordinate Hartree-Fock (GCHF) method, to evaluate its quality in molecular studies through of total energy and orbital energies (εHOMO and εHOMO-1) of the 2NiO1+ and 1LaO1+ fragments. Then, the 5s3p contracted n basis sets was enriched with one polarization function of d symmetry and the 11s8p6d and 17s11p7d basis sets were supplemented with one diffuse function by symmetry for the Ni and La atoms. Finally, theses basis sets were used to calculate the total energy, moment of dipole, and total atomic charges from LaNiO3 in Cs space group. The analysis of those properties showed that is reasonable to believe that LaNiO3 does not present piezoelectric properties. ï›™ 2007 Trade Science Inc. - INDIA