### Abstract

Slow ion-atom collisions can be described within a first-principles molecular dynamics based on eikonal wave functions for the nuclei and the time- dependent Hartree-Fock (TDHF) approximation for electrons that self-consistently couples the electronic and nuclear degrees of freedom. By expanding the molecular Orbitals in traveling atomic orbitals containing electron translation factors, it is possible to eliminate spurious couplings between same-center orbitals at asymptotic distances, and this generates a term in the density matrix equations proportional to the nuclear accelerations. We examine the effect of this acceleration term on Löwdin atomic populations for H^{+} + H(1s) and He^{2+} + H(1s) collisions, for varying collision energies and impact parameters. We find significant increases in atomic populations for an intermediate range of energies going from several tens to several hundreds of electron volts, and for low impact parameters, in the case of the H^{+} + H(1s) collision.

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

Pages (from-to) | 361-366 |

Number of pages | 6 |

Journal | International Journal of Quantum Chemistry |

Volume | 75 |

Issue number | 4-5 |

State | Published - 1999 |

Externally published | Yes |

### Fingerprint

### Keywords

- Density matrix
- Quantum molecular dynamics
- Time-dependent Hartree-Fock

### ASJC Scopus subject areas

- Physical and Theoretical Chemistry

### Cite this

*International Journal of Quantum Chemistry*,

*75*(4-5), 361-366.

**Acceleration effects in slow ion-atom collisions from a first-principles dynamics.** / Thorndyke, B.; Micha, D. A.; Runge, Keith A.

Research output: Contribution to journal › Article

*International Journal of Quantum Chemistry*, vol. 75, no. 4-5, pp. 361-366.

}

TY - JOUR

T1 - Acceleration effects in slow ion-atom collisions from a first-principles dynamics

AU - Thorndyke, B.

AU - Micha, D. A.

AU - Runge, Keith A

PY - 1999

Y1 - 1999

N2 - Slow ion-atom collisions can be described within a first-principles molecular dynamics based on eikonal wave functions for the nuclei and the time- dependent Hartree-Fock (TDHF) approximation for electrons that self-consistently couples the electronic and nuclear degrees of freedom. By expanding the molecular Orbitals in traveling atomic orbitals containing electron translation factors, it is possible to eliminate spurious couplings between same-center orbitals at asymptotic distances, and this generates a term in the density matrix equations proportional to the nuclear accelerations. We examine the effect of this acceleration term on Löwdin atomic populations for H+ + H(1s) and He2+ + H(1s) collisions, for varying collision energies and impact parameters. We find significant increases in atomic populations for an intermediate range of energies going from several tens to several hundreds of electron volts, and for low impact parameters, in the case of the H+ + H(1s) collision.

AB - Slow ion-atom collisions can be described within a first-principles molecular dynamics based on eikonal wave functions for the nuclei and the time- dependent Hartree-Fock (TDHF) approximation for electrons that self-consistently couples the electronic and nuclear degrees of freedom. By expanding the molecular Orbitals in traveling atomic orbitals containing electron translation factors, it is possible to eliminate spurious couplings between same-center orbitals at asymptotic distances, and this generates a term in the density matrix equations proportional to the nuclear accelerations. We examine the effect of this acceleration term on Löwdin atomic populations for H+ + H(1s) and He2+ + H(1s) collisions, for varying collision energies and impact parameters. We find significant increases in atomic populations for an intermediate range of energies going from several tens to several hundreds of electron volts, and for low impact parameters, in the case of the H+ + H(1s) collision.

KW - Density matrix

KW - Quantum molecular dynamics

KW - Time-dependent Hartree-Fock

UR - http://www.scopus.com/inward/record.url?scp=0343012698&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0343012698&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0343012698

VL - 75

SP - 361

EP - 366

JO - International Journal of Quantum Chemistry

JF - International Journal of Quantum Chemistry

SN - 0020-7608

IS - 4-5

ER -