1/n-expansion and calculation of wave functions

Possibility of using 1/n-expansion for calculation of wave functions is considered. The detailed consideration of the problem is limited by the case of cut-off potentials. It is shown that corrections for anharmonicity should be taken into account at the moment of l-level occurrence in the cut-off potentials to improve the accuracy of approximation for low l values. High accuracy (≅ 5 %) of 1/n-expansion at the sero energy was supported by calculation results for the Higgs potential