### Abstract

The method of reduced density matrices for obtaining the ground-state energy of an atomic system is developed, making full use of the symmetry relations for orbital and spin angular momentum. These, together with an extensive set of Hamiltonian-dependent identities, serve to decrease the number of parameters which must be varied in the density-matrix variational principle. With only a small number of parameters required, inequalities such as the Pauli restriction can then be enforced. Numerical calculations for C++ show the relative ineffectiveness of certain low-lying geminals (in the Γ(2) expansion) in reaching the Pauli restriction limit, and thus point the way to significant improvement.

Original language | English (US) |
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Pages (from-to) | 310-315 |

Number of pages | 6 |

Journal | Physical Review A |

Volume | 2 |

Issue number | 2 |

DOIs | |

State | Published - Jan 1 1970 |

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### ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics

### Cite this

*Physical Review A*,

*2*(2), 310-315. https://doi.org/10.1103/PhysRevA.2.310