An integral-factorized implementation of the driven similarity renormalization group second-order multireference perturbation theory.

@article{Hannon2016AnII,
  title={An integral-factorized implementation of the driven similarity renormalization group second-order multireference perturbation theory.},
  author={Kevin P Hannon and Chenyang Li and Francesco A. Evangelista},
  journal={The Journal of chemical physics},
  year={2016},
  volume={144 20},
  pages={
          204111
        }
}
We report an efficient implementation of a second-order multireference perturbation theory based on the driven similarity renormalization group (DSRG-MRPT2) [C. Li and F. A. Evangelista, J. Chem. Theory Comput. 11, 2097 (2015)]. Our implementation employs factorized two-electron integrals to avoid storage of large four-index intermediates. It also exploits the block structure of the reference density matrices to reduce the computational cost to that of second-order Møller-Plesset perturbation… 
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