In L 2 (R d ), we consider an elliptic differential operator A ε = − div g(x/ε)∇ + ε −2 V (x/ε), ε > 0, with periodic coefficients. For the nonstationary Schrödinger equation with the Hamiltonian A ε , analogs of homogenization problems related to an arbitrary point of the dispersion relation of the operator A 1 are studied (the so called high-energy homogenization). For the solutions of the Cauchy problems for these equations with special initial data, approximations in L 2 (R d )-norm for small ε are obtained.