### Abstract

The energy of a system which is described by a Hamiltonian which includes at most two-particle interactions can be expressed in terms of the second order reduced density matrix. However, for the 2-matrix to have proper symmetry is a weaker condition than requiring that the wavefunction be antisymmetric, which is called the N-representability problem, a problem of long term interest. Coleman [Reduced Density Matrices: Coulson's Challenge, Springer, New York, 2000] however, proposed an algorithm which ensures N-representability. In this Letter we examine the algorithm and show its connection to the full configuration interaction method and the contracted Schroedinger equation.

Original language | English (US) |
---|---|

Pages (from-to) | 263-269 |

Number of pages | 7 |

Journal | Chemical Physics Letters |

Volume | 355 |

Issue number | 3-4 |

DOIs | |

State | Published - Apr 2 2002 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Physical and Theoretical Chemistry
- Spectroscopy
- Atomic and Molecular Physics, and Optics

### Cite this

*Chemical Physics Letters*,

*355*(3-4), 263-269. https://doi.org/10.1016/S0009-2614(02)00239-7

**Ensuring N-representability : Coleman's algorithm.** / Beste, A.; Runge, Keith A; Bartlett, R.

Research output: Contribution to journal › Article

*Chemical Physics Letters*, vol. 355, no. 3-4, pp. 263-269. https://doi.org/10.1016/S0009-2614(02)00239-7

}

TY - JOUR

T1 - Ensuring N-representability

T2 - Coleman's algorithm

AU - Beste, A.

AU - Runge, Keith A

AU - Bartlett, R.

PY - 2002/4/2

Y1 - 2002/4/2

N2 - The energy of a system which is described by a Hamiltonian which includes at most two-particle interactions can be expressed in terms of the second order reduced density matrix. However, for the 2-matrix to have proper symmetry is a weaker condition than requiring that the wavefunction be antisymmetric, which is called the N-representability problem, a problem of long term interest. Coleman [Reduced Density Matrices: Coulson's Challenge, Springer, New York, 2000] however, proposed an algorithm which ensures N-representability. In this Letter we examine the algorithm and show its connection to the full configuration interaction method and the contracted Schroedinger equation.

AB - The energy of a system which is described by a Hamiltonian which includes at most two-particle interactions can be expressed in terms of the second order reduced density matrix. However, for the 2-matrix to have proper symmetry is a weaker condition than requiring that the wavefunction be antisymmetric, which is called the N-representability problem, a problem of long term interest. Coleman [Reduced Density Matrices: Coulson's Challenge, Springer, New York, 2000] however, proposed an algorithm which ensures N-representability. In this Letter we examine the algorithm and show its connection to the full configuration interaction method and the contracted Schroedinger equation.

UR - http://www.scopus.com/inward/record.url?scp=0011169664&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0011169664&partnerID=8YFLogxK

U2 - 10.1016/S0009-2614(02)00239-7

DO - 10.1016/S0009-2614(02)00239-7

M3 - Article

AN - SCOPUS:0011169664

VL - 355

SP - 263

EP - 269

JO - Chemical Physics Letters

JF - Chemical Physics Letters

SN - 0009-2614

IS - 3-4

ER -