Аннотация
The asymptotics of the eigenvalues is received, and conclusions about the stability and instability of the basis property of the system of eigenfunctions and associated functions of the Schrodinger operator for various occasions of the disarmed regularity of the boundary conditions are done.In the paper there is considered the Samarsky -Ionkin spectral problem for the Schrodinger equation with an integral perturbation in the boundary conditions.It is assumed that the unperturbed problem has a system of eigenfunctions forming a Riesz basis in L 2 (0, 1) .It is shown that the basis property of the systems of root functions of a problem can be varied under any arbitrarily small variation of the kernel of the integral perturbation.