Structural distortions and orbital ordering in LaTiO3 and YTiO3
  Theoretical investigations of the electronic, magnetic and structural properties of LaTiO3 and YTiO3 have been made. In the framework of GGA and GGA+U scheme we analyzed the effect of the local Coulomb interaction (U) value on the atomic forces acting in the experimental structure. The optimal parameters of the electron-electron on-site interactions as well as the orbital configurations and magnetic properties are determined. 
S.Okatov, A.Poteryaev, A.Lichtenstein