Article

# Calibration-quality adiabatic potential energy surfaces for H-3(+) and its isotopologues

Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.

The Journal of Chemical Physics (Impact Factor: 3.12). 05/2012; 136(18):184303. DOI: 10.1063/1.4711756 Source: PubMed

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Attila Csaszar, Mar 11, 2014 Available from: Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

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**ABSTRACT:**Introducing different rotational and vibrational masses in the nuclear-motion Hamiltonian is a simple phenomenological way to model rovibrational non-adiabaticity. It is shown on the example of the molecular ion H3 (+), for which a global adiabatic potential energy surface accurate to better than 0.1 cm(-1) exists [M. Pavanello, L. Adamowicz, A. Alijah, N. F. Zobov, I. I. Mizus, O. L. Polyansky, J. Tennyson, T. Szidarovszky, A. G. Császár, M. Berg et al., Phys. Rev. Lett. 108, 023002 (2012)], that the motion-dependent mass concept yields much more accurate rovibrational energy levels but, unusually, the results are dependent upon the choice of the embedding of the molecule-fixed frame. Correct degeneracies and an improved agreement with experimental data are obtained if an Eckart embedding corresponding to a reference structure of D3h point-group symmetry is employed. The vibrational mass of the proton in H3 (+) is optimized by minimizing the root-mean-square (rms) deviation between the computed and recent high-accuracy experimental transitions. The best vibrational mass obtained is larger than the nuclear mass of the proton by approximately one third of an electron mass, m opt ,p ((v))=m nuc ,p+0.31224me. This optimized vibrational mass, along with a nuclear rotational mass, reduces the rms deviation of the experimental and computed rovibrational transitions by an order of magnitude. Finally, it is shown that an extension of the algorithm allowing the use of motion-dependent masses can deal with coordinate-dependent mass surfaces in the rovibrational Hamiltonian, as well.The Journal of Chemical Physics 10/2014; 141(15):154111. DOI:10.1063/1.4897566 · 3.12 Impact Factor - [Show abstract] [Hide abstract]

**ABSTRACT:**On the basis of both experiment and theory, accurate rotational–vibrational line positions and energy levels, with associated critically reviewed labels and uncertainties, are reported for the ground electronic state of the H3+ molecular ion. An improved MARVEL algorithm is used to determine the validated experimental levels and their self-consistent uncertainties from a set of 1610 measured transitions and associated uncertainties, coming from 26 sources. 1410 transitions have been validated for ortho-H3+ and para-H3+, 78 belong to floating components of the spectroscopic network (SN) investigated and thus left unvalidated, while 122 measured transitions had to be excluded from the MARVEL analysis for one reason or another. The spectral range covered by the experiments is 7–16 506 cm–1 . Altogether 13 vibrational band origins are reported, the highest J value, where J stands for the rotational quantum number, for which energy levels are validated is 12. The MARVEL energy levels are checked against ones determined from accurate variational nuclear motion computations employing the best available adiabatic ab initio potential energy surface and exact kinetic energy operators. The number of validated and thus recommended experimental-quality rovibrational energy levels is 652, of which 259 belong to ortho-H3+ and 393 to para-H3+. There are 105 further energy levels within floating components of the SN. The variational computations have been performed both without and with a simple nonadiabatic correction, whereby nonadiabaticity is modeled by the use of a non-nuclear vibrational mass. The lists of validated lines and levels for H3+ are deposited in the Supporting Information to this paper.Journal of Chemical Theory and Computation 11/2013; 9(12):5471–5478. DOI:10.1021/ct4004355 · 5.31 Impact Factor - [Show abstract] [Hide abstract]

**ABSTRACT:**We have used a Lanczos algorithm with a nondirect product basis to compute energy levels of \hhh with $J$ values as large as 46. Energy levels computed on the potential surface of M.~Pavanello, \ea (\JCP {136}{184303}{2012}) agree well with previous calculations for low $J$ values.The Journal of Physical Chemistry A 03/2013; 117(39). DOI:10.1021/jp312027s · 2.78 Impact Factor