### Abstract

Original language | English |
---|---|

Pages (from-to) | - |

Journal | Physical Review A - Atomic, Molecular, and Optical Physics |

Volume | 71 |

Issue number | 4 |

Publication status | Published - 2005 |

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*Physical Review A - Atomic, Molecular, and Optical Physics*,

*71*(4), -.

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*Physical Review A - Atomic, Molecular, and Optical Physics*, vol. 71, no. 4, pp. -.

**Higher-order Cn dispersion coefficients for the alkali-metal atoms.** / Mitroy, James; Bromley, Michael.

Research output: Contribution to journal › Article › Research › peer-review

TY - JOUR

T1 - Higher-order Cn dispersion coefficients for the alkali-metal atoms

AU - Mitroy, James

AU - Bromley, Michael

PY - 2005

Y1 - 2005

N2 - The van der Waals coefficients, from C11 through to C16 resulting from second-, third-, and fourth-order perturbation theory are estimated for the alkali-metal (Li, Na, K, and Rb) atoms. The dispersion coefficients are also computed for all possible combinations of the alkali-metal atoms and hydrogen. The parameters are determined from sum rules after diagonalizing a semiempirical fixed core Hamiltonian in a large basis. Comparisons of the radial dependence of the Cnrn potentials give guidance as to the radial regions in which the various higher-order terms can be neglected. It is seen that including terms up to C10r10 results in a dispersion interaction that is accurate to better than 1% whenever the inter-nuclear spacing is larger than 20a0. This level of accuracy is mainly achieved due to the fortuitous cancellation between the repulsive (C11,C13,C15) and attractive (C12,C14,C16) dispersion forces. � 2005 The American Physical Society.

AB - The van der Waals coefficients, from C11 through to C16 resulting from second-, third-, and fourth-order perturbation theory are estimated for the alkali-metal (Li, Na, K, and Rb) atoms. The dispersion coefficients are also computed for all possible combinations of the alkali-metal atoms and hydrogen. The parameters are determined from sum rules after diagonalizing a semiempirical fixed core Hamiltonian in a large basis. Comparisons of the radial dependence of the Cnrn potentials give guidance as to the radial regions in which the various higher-order terms can be neglected. It is seen that including terms up to C10r10 results in a dispersion interaction that is accurate to better than 1% whenever the inter-nuclear spacing is larger than 20a0. This level of accuracy is mainly achieved due to the fortuitous cancellation between the repulsive (C11,C13,C15) and attractive (C12,C14,C16) dispersion forces. � 2005 The American Physical Society.

KW - Dispersion coefficients

KW - Van der Waals coefficients

KW - Hamiltonians

KW - Hydrogen

KW - Parameter estimation

KW - Perturbation techniques

KW - Van der Waals forces

KW - Alkali metals

M3 - Article

VL - 71

SP - -

JO - Physical Review A

JF - Physical Review A

SN - 1050-2947

IS - 4

ER -