QUANTUM-CHEMISTRY BY RANDOM-WALK - METHOD OF SUCCESSIVE CORRECTIONS

The random-walk method of solving the Schrödinger equation is reformulated to allow the direct calculation of the difference δ between a true wavefunction ψ and a trial wave-function ψ0. For a trial wavefunction from any source the difference δ may be calculated and used to correct the trial wavefunction. Successive calculations offer the possibility of further corrections and wavefunctions of unlimited accuracy. The calculation of δ is illustrated for the cases of the particle-in-a-box and the hydrogen atom. Energies are determined directly from the random-walk calculations and indirectly from computation of the expectation values for the corrected wavefunctions. © 1979.