Orbital angular momentum constraints in the variational optimization of the two-electron reduced-density matrix

  title={Orbital angular momentum constraints in the variational optimization of the two-electron reduced-density matrix},
  author={Run R Li and A. Eugene DePrince},
  journal={Physical Review A},
The direct variational determination of the two-electron reduced-density matrix (2-RDM) is usually carried out under the assumption that the 2-RDM is a real-valued quantity. However, in systems that possess orbital angular momentum symmetry, the description of states with a well-defined, non-zero z-projection of the orbital angular momentum requires a complex-valued 2-RDM. We consider a semidefinite program suitable for the direct optimization of a complex-valued 2-RDM and explore the role of… 
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