skip to main content

SciTech ConnectSciTech Connect

Title: Rotational study of the NH{sub 3}–CO complex: Millimeter-wave measurements and ab initio calculations

The rotational spectrum of the van der Waals complex NH{sub 3}–CO has been measured with the intracavity OROTRON jet spectrometer in the frequency range of 112–139 GHz. Newly observed and assigned transitions belong to the K = 0–0, K = 1–1, K = 1–0, and K = 2–1 subbands correlating with the rotationless (j{sub k}){sub NH3} = 0{sub 0} ground state of free ortho-NH{sub 3} and the K = 0–1 and K = 2–1 subbands correlating with the (j{sub k}){sub NH3} = 1{sub 1} ground state of free para-NH{sub 3}. The (approximate) quantum number K is the projection of the total angular momentum J on the intermolecular axis. Some of these transitions are continuations to higher J values of transition series observed previously [C. Xia et al., Mol. Phys. 99, 643 (2001)], the other transitions constitute newly detected subbands. The new data were analyzed together with the known millimeter-wave and microwave transitions in order to determine the molecular parameters of the ortho-NH{sub 3}–CO and para-NH{sub 3}–CO complexes. Accompanying ab initio calculations of the intermolecular potential energy surface (PES) of NH{sub 3}–CO has been carried out at the explicitly correlated coupled cluster level of theory with single, double, and perturbative triplemore » excitations and an augmented correlation-consistent triple zeta basis set. The global minimum of the five-dimensional PES corresponds to an approximately T-shaped structure with the N atom closest to the CO subunit and binding energy D{sub e} = 359.21 cm{sup −1}. The bound rovibrational levels of the NH{sub 3}–CO complex were calculated for total angular momentum J = 0–6 on this intermolecular potential surface and compared with the experimental results. The calculated dissociation energies D{sub 0} are 210.43 and 218.66 cm{sup −1} for ortho-NH{sub 3}–CO and para-NH{sub 3}–CO, respectively.« less
Authors:
 [1] ;  [2] ; ;  [1] ; ; ;  [3] ;  [4] ;  [5] ;  [6] ;  [7]
  1. I. Physikalisches Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne (Germany)
  2. (Russian Federation)
  3. Institute of Spectroscopy, Russian Academy of Sciences, Fizicheskaya Str. 5, 142190 Troitsk, Moscow (Russian Federation)
  4. Department of Optics and Spectroscopy, Tomsk State University, 36 Lenin av., 634050 Tomsk (Russian Federation)
  5. Université de Grenoble Alpes, IPAG, F-38000 Grenoble (France)
  6. (France)
  7. Theoretical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen (Netherlands)
Publication Date:
OSTI Identifier:
22415536
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 11; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; AMMONIA; AMMONIUM COMPLEXES; ANGULAR MOMENTUM; ATOMS; BINDING ENERGY; CARBON MONOXIDE; COMPARATIVE EVALUATIONS; CORRELATIONS; DISSOCIATION ENERGY; EXCITATION; GHZ RANGE; GROUND STATES; MICROWAVE RADIATION; POTENTIAL ENERGY; POTENTIALS; ROTATIONAL STATES; SURFACES; VAN DER WAALS FORCES