A model is proposed for the LaTiO3 compound, which allows for the strong coupling of the lattice, orbital, and magnetic subsystems of this crystal. The interaction of the lattice with the electronic structure of the LaTiO3 compound is described by the vibronic Hamiltonian with the constants calculated using the ab initio Hartree-Fock-Roothaan method with the inclusion of the electron correlations. It is demonstrated that a considerable contribution to the formation of the orbital structure of the LaTiO3 compound is made by the next-nearest neighbors of the Ti3+ ion. The orbital-dependent superexchange interactions in LaTiO3 are described within the Hubbard model and agree well with experiment.