### Abstract

Nonadiabatic variational calculations for the positronium molecule, Ps2 = (e+e )i, a cluster composed of two electrons and two positrons, is the subject of theoretical investigation. In particular, calculations of the twophoton annihilation rate as well as estimation of the lifetime at the nonrelativistic level of theory are presented in detail. In all calculations the nonadiabatic four-body wave function is expanded in terms of explicitly correlated Gaussian functions. The energy of the center-of-mass motion is effectively eliminated from the total nonrelativistic energy through the modified variational principle based on the internal Hamiltonian. With the wave function expanded in terms of 300 basis functions, which leads to a total energy equal to -0.515 980 au and a binding energy equal to 0.435 eV, the lifetime of the system is estimated to be 0.907 ns.

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

Pages (from-to) | 6266-6271 |

Number of pages | 6 |

Journal | Journal of Physical Chemistry |

Volume | 100 |

Issue number | 15 |

State | Published - 1996 |

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### ASJC Scopus subject areas

- Physical and Theoretical Chemistry
- Engineering(all)

### Cite this

*Journal of Physical Chemistry*,

*100*(15), 6266-6271.

**Lifetime of positronium molecule. study with boys' explicitly correlated gaussians.** / Kozlowski, Pawel M.; Adamowicz, Ludwik.

Research output: Contribution to journal › Article

*Journal of Physical Chemistry*, vol. 100, no. 15, pp. 6266-6271.

}

TY - JOUR

T1 - Lifetime of positronium molecule. study with boys' explicitly correlated gaussians

AU - Kozlowski, Pawel M.

AU - Adamowicz, Ludwik

PY - 1996

Y1 - 1996

N2 - Nonadiabatic variational calculations for the positronium molecule, Ps2 = (e+e )i, a cluster composed of two electrons and two positrons, is the subject of theoretical investigation. In particular, calculations of the twophoton annihilation rate as well as estimation of the lifetime at the nonrelativistic level of theory are presented in detail. In all calculations the nonadiabatic four-body wave function is expanded in terms of explicitly correlated Gaussian functions. The energy of the center-of-mass motion is effectively eliminated from the total nonrelativistic energy through the modified variational principle based on the internal Hamiltonian. With the wave function expanded in terms of 300 basis functions, which leads to a total energy equal to -0.515 980 au and a binding energy equal to 0.435 eV, the lifetime of the system is estimated to be 0.907 ns.

AB - Nonadiabatic variational calculations for the positronium molecule, Ps2 = (e+e )i, a cluster composed of two electrons and two positrons, is the subject of theoretical investigation. In particular, calculations of the twophoton annihilation rate as well as estimation of the lifetime at the nonrelativistic level of theory are presented in detail. In all calculations the nonadiabatic four-body wave function is expanded in terms of explicitly correlated Gaussian functions. The energy of the center-of-mass motion is effectively eliminated from the total nonrelativistic energy through the modified variational principle based on the internal Hamiltonian. With the wave function expanded in terms of 300 basis functions, which leads to a total energy equal to -0.515 980 au and a binding energy equal to 0.435 eV, the lifetime of the system is estimated to be 0.907 ns.

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M3 - Article

AN - SCOPUS:0030125590

VL - 100

SP - 6266

EP - 6271

JO - Journal of Physical Chemistry

JF - Journal of Physical Chemistry

SN - 0022-3654

IS - 15

ER -