Hypernodal Quantum Monte Carlo
Prof.Dr. M.H.Kalos
Lawrence Livermore National Laboratories, U.S.A.
Mercredi23 juin 2004, 11h00
We propose a novel method for relaxing the nodal constraint of quantum
Monte Carlo in a stable way. We consider a pair of walkers that diffuse
in a higher-dimensional space, and construct a functional that vanishes if
the trial functions are exact. Each walker can violate the original
fixed-node constraint, but the pair is subject to a new constraint.
Therefore it yields upper bounds to the electronic energy that are lower
than those given by the existing fixed-node method while using the same
trial function.