Communication: Rigidity of the molecular ion H{sub 5}{sup +}

Journal Article · Fri Feb 07 04:00:00 EST 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4864360· OSTI ID:22255141

Fábri, Csaba ^[1]; Sarka, János; Császár, Attila G. ^[1]

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1. Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, Eötvös University, H-1117 Budapest, Pázmány Péter sétány 1/A (Hungary)

The fourth-age quantum chemical code GENIUSH is used for the variational determination of rotational-vibrational energy levels corresponding to reduced- and full-dimensional models of H{sub 5}{sup +}, a molecular ion exhibiting several strongly coupled large-amplitude motions. The computations are supplemented with one- and two-dimensional analytic results which help to understand the peculiar rovibrational energy-level structure computed correctly for the first time. An unusual aspect of the results is that the canonical Eckart-embedding of molecule-fixed axes, a cornerstone of the computational spectroscopy of semirigid molecules, is found to be inadequate. Furthermore, it is shown that while the 1D “active torsion” model provides proper results when compared to the full, 9D treatment, models excluding the torsion have limited physical significance. The structure of the rovibrational energy levels of H{sub 5}{sup +} proves that this is a prototypical astructural molecule: the rotational and vibrational level spacings are of the same order of magnitude and the level structure drastically deviates from that computed via perturbed rigid-rotor and harmonic-oscillator models.

• OSTI ID: 22255141
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 5 Vol. 140; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ENERGY LEVELS
HARMONIC OSCILLATOR MODELS
MOLECULAR IONS
SPECTROSCOPY
TORSION
TWO-DIMENSIONAL CALCULATIONS