Improved Fast Randomized Iteration Approach to Full Configuration Interaction
Improved Fast Randomized Iteration Approach to Full Configuration Interaction
We present three modifications to our recently introduced fast randomized iteration method for full configuration interaction (FCI-FRI) and investigate their effects on the method's performance for Ne, H2O, and N2. The initiator approximation, originally developed for full configuration interaction quantum Monte Carlo, significantly reduces statistical error in FCI-FRI when few …