A comparison of some lower bounds for eigenvalues of Schrodinger's equation
Peter Hornby, Michael N. Barber · Journal of Physics A Mathematical and General · 1983
A method proposed recently by Singh (1981) of finding lower bounds to the eigen-energies of Schrodinger's equation is reviewed and compared with the methods of Bazley and Fox (1961) and of Lowdin (1965). Numerical results for an anharmonic oscillator suggest that the Singh method is less accurate than the others, but unlike the Lowdin single bracketing function technique does not suffer from any eigenvalue ordering problems.