Computing the energy of a water molecule using multideterminants: a simple, efficient algorithm.
Quantum Monte Carlo (QMC) methods such as variational Monte Carlo and fixed node diffusion Monte Carlo depend heavily on the quality of the trial wave function. Although Slater-Jastrow wave functions are the most commonly used variational ansatz in electronic structure, more sophisticated wave functions are critical to ascertaining new physics. One such wave function is the multi-Slater-Jastrow wave function which consists of a Jastrow function multiplied by the sum of Slater determinants. In this paper we describe a method for working with these wave functions in QMC codes that is easy to implement, efficient both in computational speed as well as memory, and easily parallelized. The computational cost scales quadratically with particle number making this scaling no worse than the single determinant case and linear with the total number of excitations. Additionally, we implement this method and use it to compute the ground state energy of a water molecule.
Princeton Center For Theoretical Science, Princeton University, Princeton, New Jersey 08544, USA. bclark@princeton.edu
Bryan K
BK
Clark
Miguel A
MA
Morales
Jeremy
J
McMinis
Jeongnim
J
Kim
Gustavo E
GE
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