The relativistic complete active-space second-order perturbation theory with the four-component Dirac Hamiltonian.

@article{Abe2006TheRC,
  title={The relativistic complete active-space second-order perturbation theory with the four-component Dirac Hamiltonian.},
  author={Minori Abe and Takahito Nakajima and Kimihiko Hirao},
  journal={The Journal of chemical physics},
  year={2006},
  volume={125 23},
  pages={234110}
}
The relativistic complete active-space second-order perturbation theory (CASPT2) is developed for the four-component relativistic Hamiltonian. The present method can describe the near-degenerated and dissociated electronic states of molecules involving atoms of heavy elements. The present approach is less expensive than the relativistic multireference… CONTINUE READING