### Abstract

We review a recent development in high-accuracy non-Born-Oppenheimer calculations of atomic and molecular systems in a basis of explicitly correlated Gaussian functions. Much of the recent progress in this area is due to the derivation and implementation of analytical gradients of the energy functional with respect to variational linear and non-linear parameters of the basis functions. This method has been used to obtain atomic and molecular ground and excited state energies and the corresponding wave functions with accuracy that exceeds previous calculations. Further, we have performed the first calculations of non-linear electrical properties of molecules without the Born-Oppenheimer approximation for systems with more than one electron. The results for the dipole moments of such systems as HD and LiH agree very well with experiment. After reviewing our non-Born-Oppenheimer results we will discuss ways this method can be extended to deal with larger molecular systems with and without an external perturbation.

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

Pages (from-to) | 1491-1501 |

Number of pages | 11 |

Journal | Physical Chemistry Chemical Physics |

Volume | 5 |

Issue number | 8 |

DOIs | |

State | Published - Apr 15 2003 |

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### ASJC Scopus subject areas

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

### Cite this

*Physical Chemistry Chemical Physics*,

*5*(8), 1491-1501. https://doi.org/10.1039/b211193d

**Non-Born-Oppenheimer calculations of atoms and molecules.** / Cafiero, Mauricio; Bubin, Sergiy; Adamowicz, Ludwik.

Research output: Contribution to journal › Article

*Physical Chemistry Chemical Physics*, vol. 5, no. 8, pp. 1491-1501. https://doi.org/10.1039/b211193d

}

TY - JOUR

T1 - Non-Born-Oppenheimer calculations of atoms and molecules

AU - Cafiero, Mauricio

AU - Bubin, Sergiy

AU - Adamowicz, Ludwik

PY - 2003/4/15

Y1 - 2003/4/15

N2 - We review a recent development in high-accuracy non-Born-Oppenheimer calculations of atomic and molecular systems in a basis of explicitly correlated Gaussian functions. Much of the recent progress in this area is due to the derivation and implementation of analytical gradients of the energy functional with respect to variational linear and non-linear parameters of the basis functions. This method has been used to obtain atomic and molecular ground and excited state energies and the corresponding wave functions with accuracy that exceeds previous calculations. Further, we have performed the first calculations of non-linear electrical properties of molecules without the Born-Oppenheimer approximation for systems with more than one electron. The results for the dipole moments of such systems as HD and LiH agree very well with experiment. After reviewing our non-Born-Oppenheimer results we will discuss ways this method can be extended to deal with larger molecular systems with and without an external perturbation.

AB - We review a recent development in high-accuracy non-Born-Oppenheimer calculations of atomic and molecular systems in a basis of explicitly correlated Gaussian functions. Much of the recent progress in this area is due to the derivation and implementation of analytical gradients of the energy functional with respect to variational linear and non-linear parameters of the basis functions. This method has been used to obtain atomic and molecular ground and excited state energies and the corresponding wave functions with accuracy that exceeds previous calculations. Further, we have performed the first calculations of non-linear electrical properties of molecules without the Born-Oppenheimer approximation for systems with more than one electron. The results for the dipole moments of such systems as HD and LiH agree very well with experiment. After reviewing our non-Born-Oppenheimer results we will discuss ways this method can be extended to deal with larger molecular systems with and without an external perturbation.

UR - http://www.scopus.com/inward/record.url?scp=0037446921&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037446921&partnerID=8YFLogxK

U2 - 10.1039/b211193d

DO - 10.1039/b211193d

M3 - Article

VL - 5

SP - 1491

EP - 1501

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 8

ER -