Improved Fast Randomized Iteration Approach to Full Configuration Interaction.

@article{Greene2020ImprovedFR,
  title={Improved Fast Randomized Iteration Approach to Full Configuration Interaction.},
  author={Samuel M. Greene and Robert J. Webber and Jonathan Weare and Timothy C. Berkelbach},
  journal={Journal of chemical theory and computation},
  year={2020}
}
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 samples are used in compression operations, enabling its application to larger chemical systems. The semi-stochastic… 

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