Configuration Interaction Monte Carlo with Coupled Clusters Wave Functions

Quantum Monte Carlo algorithms in Fock space have gained popularity in the last few years. Here we review the Configuration Interaction Monte Carlo (CIMC) algorithm. CIMC provides a way to implement the imaginary time propagation projecting the ground state of a given Hamiltonian in a model Hilbert space that (1) makes use of an importance function, and in particular of the wave function computed in a Coupled Cluster calculation, and (2) exploits a continuous time algorithm to eliminate the approximations due to the use of a finite imaginary time step. Some results and discussions from the implementation in the three-dimensional electron gas and first row atoms are also presented.