Polyansky, OL;
Ovsyannikov, RI;
Kyuberis, AA;
Lodi, L;
Tennyson, J;
Yachmenev, A;
Yurchenko, SN;
(2016)
Calculation of rotation-vibration energy levels of the ammonia molecule based on an ab initio potential energy surface.
Journal of Molecular Spectroscopy
, 327
pp. 21-30.
10.1016/j.jms.2016.08.003.
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Abstract
An ab initio potential energy surface (PES) for gas-phase ammonia NH3 has been computed using the methodology pioneered for water (Polyansky et al., 2013). Multireference configuration interaction calculations are performed at about 50 000 points using the aug-cc-pCVQZ and aug-cc-pCV5Z basis sets and basis set extrapolation. Relativistic and adiabatic surfaces are also computed. The points are fitted to a suitable analytical form, producing the most accurate ab initio PES for this molecule available. The rotation-vibration energy levels are computed using nuclear motion program TROVE in both linearised and curvilinear coordinates. Better convergence is obtained using curvilinear coordinates. Our results are used to assign the visible spectrum of recorded by Coy and Lehmann (1986). Rotation-vibration energy levels for the isotopologues NH2D, NHD2, ND3 and are also given. An ab initio value for the dissociation energy of is also presented.
| Type: | Article |
|---|---|
| Title: | Calculation of rotation-vibration energy levels of the ammonia molecule based on an ab initio potential energy surface |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.jms.2016.08.003 |
| Publisher version: | https://doi.org/10.1016/j.jms.2016.08.003 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Ammonia, Global potential energy surface, Ab initio, Rovibrational levels, Dissociation energy |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10054348 |
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