  We present a quantum critical behavior of the renormalized single-particle
Wannier function, calculated in the Gutzwiller correlated state near the
insulator-metal transition (IMT) for cubic lattices. The wave function size and
its maximum, as well as the system energy scale with increasing lattice
parameter $R$ as $R^{n}$. Such scaling is interpreted as the evidence of a
dominant role of the Coulomb repulsion. Relation of the insulator-metal
transition lattice-parameter value $R=R_{C}$ to the original {\em Mott
criterion\} is obtained. The method is tested by comparing our results with the
exact approach for the Hubbard chain.
