  The variational theory of momentum dependent local-ansatz (MLA) has been
generalized by introducing a hybrid (HB) wavefunction as a starting
wavefunction, whose potential can flexibly change from the Hartree-Fock type to
the alloy-analogy type by varying a weighting factor from zero to one.
Numerical results based on the half-filled band Hubbard model on the hypercubic
lattice in infinite dimensions show up that the new wavefunction yields the
ground-state energy lower than that of the Gutzwiller wavefunction (GW) in the
whole Coulomb interaction regime. Calculated double occupation number is
smaller than the result of the GW in the weak Coulomb interaction regime, and
remains finite in the strong regime. Furthermore, the momentum distribution
shows a distinct momentum dependence, which is qualitatively different from
that of the GW.
