Estimating the overlap of an approximate with te eact wave function by quantum Monte Carlo methods

摘要

This work is an extensionof Langfeler, Rothstein, and Vrbik's J. Chem. Phys. 107. 8525 (1997), (LRV) algorithm that samles the "exact" ground state edistribution #PHI#_0~(2). The distribution is the same as that obtained from exactly solving the Schrodinger equation, but with a small error due to the incorrect nodes imposed on the simulation by the guiding function . B. Anderson, J. Chem. Phys. 65, 4121 (1976) #psi#, LRV applied their algorithm to estimate the expectation values of nondifferential properties for first-row atoms and ions. Our objective is show that at the same tie, with some relatively trivial modifications, the algorithm can estimate the overlap integral of #psi# with the exact wave function #PHI#_0.