dc.creator Huang, Xinchuan en_US dc.creator Schwenke, David W. en_US dc.creator Lee, Timothy J. en_US dc.date.accessioned 2009-07-29T12:40:57Z dc.date.available 2009-07-29T12:40:57Z dc.date.issued 2009 en_US dc.identifier 2009-TH-07 en_US dc.identifier.uri http://hdl.handle.net/1811/38043 dc.description X. Huang, D.W. Schwenke, and T.J. Lee, \textit{J. Chem. Phys. en_US dc.description Author Institution: MS 245-6, NASA Ames Research Center, Moffett Field, CA, 94035; MS T27B-1, NASA Ames Research Center, Moffett Field, CA, 94035; MS 245-1, NASA Ames Research Center, Moffett Field, CA, 94035 en_US dc.description.abstract A further refined, global potential energy surface (PES) is computed for the $C_{3v}$ symmetry isotopologues of ammonia, including $^{14}$NH$_3$, $^{15}$NH$_3$, $^{14}$ND$_3$ and $^{14}$NT$_3$. The refinement procedure was similar to that used in our previously reported PES \underline{\textbf{129}}, 214304 (2008).}, but now extends to higher $J$ energy levels and other isotopologues. Both the diagonal Born-Oppenheimer correction and the non-adiabatic correction were included. $J=0-6$ rovibrational energy levels and transition frequencies of $^{14}$NH$_3$ computed on this PES are in excellent agreement with HITRAN data. Statistics on nearly 4100 transitions and more than 1000 energy levels demonstrate the accuracy achieved by the state-of-the-art "Best Theory + Experiment" strategy. Most transition frequencies are of $\pm0.01-0.02$ cm$^{-1}$ accuracy. Similar accuracy has been found on $^{15}$NH$_3$ $J=0-3$ rovibrational energy levels. Several transitions and energy levels in HITRAN have been identified as unreliable or suspicious, and some have been re-assigned. For $^{14}$ND$_3$ and $^{14}$NT$_3$, $J=0-3$ calculations have been performed. Agreement for pure rotation-inversion transitions is nearly perfect, with more reliable energy levels presented. On the other hand, our $J=0$ results suggest a re-analysis on the $^{14}$ND$_3$ $\nu_1$ band origin is needed. Finally, we will discuss possible future refinements leading to an even better final PES for Ammonia. en_US dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title ACCURATE POTENTIAL ENERGY SURFACE, ROVIBRATIONAL ENERGY LEVELS, AND TRANSITIONS OF AMMONIA $C_{3v}$ ISOTOPOLOGUES: $^{14}$NH$_3$, $^{15}$NH$_3$, $^{14}$ND$_3$ and $^{14}$NT$_3$ en_US dc.type Article en_US
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