ACCURATE EVALUATION OF QUANTUM INTEGRALS

Combining an appropriate finite difference method with Richardson's ex trapolation results in a simple, highly accurate numerical method for solving a Schrodinger's equation. Important results are that error est imates are provided, and that one can extrapolate expectation values r ather than the wavefunctions to obtain highly accurate expectation val ues. We discuss the eigenvalues, the error growth in repeated Richards on's extrapolation, and show that: the expectation values calculated o n a crude mesh can be extrapolated to obtain expectation values of hig h accuracy.