### Abstract

A new D_{3h}, symmetry adapted approach to accurate calculation of high-lying rovibrational (J>0) states of floppy X_{3} triatomic molecules is presented, extending our recent work on J = O bound states of D_{3h} triatomics [Z. Bačić and J. Z. H. Zhang, Chem. Phys. Lett. 184, 513 (1991)]. Three sets of Jacobi coordinates are employed, allowing construction of basis sets with full S_{3} permutation symmetry of the three identical nuclei. Inclusion of S_{3} symmetry reduces substantially the size of the final matrix eigenvalue problem and the computational effort involved. It also assures unambiguous, correct symmetry assignment of the calculated rovibrational levels. Our method is especially suitable for rotating D_{3h} molecules with strongly coupled large amplitude motions of the three atoms. An efficient quasiadiabatic diagonalization and truncation scheme is incorporated into our methodology. Application to H_{3}
^{+} for J=1 produced the total of 426 well converged, symmetry assigned states up to ∼24 000 cm^{-1} above the ground state, far more than in any previous calculation for rotating H _{3}
^{+}.

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

Pages (from-to) | 3707-3713 |

Number of pages | 7 |

Journal | The Journal of chemical physics |

Volume | 96 |

Issue number | 5 |

State | Published - 1992 |

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### ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics

### Cite this

**High-lying rovibrational states of floppy X3 triatomics by a new D3h symmetry adapted method : Application to the H3 + molecule.** / Bacic, Zlatko; Zhang, John.

Research output: Contribution to journal › Article

*The Journal of chemical physics*, vol. 96, no. 5, pp. 3707-3713.

}

TY - JOUR

T1 - High-lying rovibrational states of floppy X3 triatomics by a new D3h symmetry adapted method

T2 - Application to the H3 + molecule

AU - Bacic, Zlatko

AU - Zhang, John

PY - 1992

Y1 - 1992

N2 - A new D3h, symmetry adapted approach to accurate calculation of high-lying rovibrational (J>0) states of floppy X3 triatomic molecules is presented, extending our recent work on J = O bound states of D3h triatomics [Z. Bačić and J. Z. H. Zhang, Chem. Phys. Lett. 184, 513 (1991)]. Three sets of Jacobi coordinates are employed, allowing construction of basis sets with full S3 permutation symmetry of the three identical nuclei. Inclusion of S3 symmetry reduces substantially the size of the final matrix eigenvalue problem and the computational effort involved. It also assures unambiguous, correct symmetry assignment of the calculated rovibrational levels. Our method is especially suitable for rotating D3h molecules with strongly coupled large amplitude motions of the three atoms. An efficient quasiadiabatic diagonalization and truncation scheme is incorporated into our methodology. Application to H3 + for J=1 produced the total of 426 well converged, symmetry assigned states up to ∼24 000 cm-1 above the ground state, far more than in any previous calculation for rotating H 3 +.

AB - A new D3h, symmetry adapted approach to accurate calculation of high-lying rovibrational (J>0) states of floppy X3 triatomic molecules is presented, extending our recent work on J = O bound states of D3h triatomics [Z. Bačić and J. Z. H. Zhang, Chem. Phys. Lett. 184, 513 (1991)]. Three sets of Jacobi coordinates are employed, allowing construction of basis sets with full S3 permutation symmetry of the three identical nuclei. Inclusion of S3 symmetry reduces substantially the size of the final matrix eigenvalue problem and the computational effort involved. It also assures unambiguous, correct symmetry assignment of the calculated rovibrational levels. Our method is especially suitable for rotating D3h molecules with strongly coupled large amplitude motions of the three atoms. An efficient quasiadiabatic diagonalization and truncation scheme is incorporated into our methodology. Application to H3 + for J=1 produced the total of 426 well converged, symmetry assigned states up to ∼24 000 cm-1 above the ground state, far more than in any previous calculation for rotating H 3 +.

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UR - http://www.scopus.com/inward/citedby.url?scp=0000320887&partnerID=8YFLogxK

M3 - Article

VL - 96

SP - 3707

EP - 3713

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 5

ER -