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Ab initio characterization of C-5

Masso, H.; Veryazov, Valera LU ; Malmqvist, Per-Åke LU ; Roos, Björn LU and Senent, M. L. (2007) In Journal of Chemical Physics 127(15).
Abstract
In this paper, the structure and spectroscopic parameters of the C-5 cluster are determined using multiconfigurational quantum chemical methods as implemented in the MOLCAS software. A number of spectroscopic properties (band center positions, l-doubling parameters, and rotational constants) have been characterized. From the new results, the assignments of previous astrophysical observations [J. Goicoechea , Astrophys. J. 609, 225 (2004)] are discussed. A detailed exploration of the global potential energy surface confirms that C-5 has a X (1)Sigma(+)(g) linear isomer of prominent stability and, at least, three minimum energy structures showing singlet electronic ground states. Two of them are cyclic and one has a nonplanar geometry.... (More)
In this paper, the structure and spectroscopic parameters of the C-5 cluster are determined using multiconfigurational quantum chemical methods as implemented in the MOLCAS software. A number of spectroscopic properties (band center positions, l-doubling parameters, and rotational constants) have been characterized. From the new results, the assignments of previous astrophysical observations [J. Goicoechea , Astrophys. J. 609, 225 (2004)] are discussed. A detailed exploration of the global potential energy surface confirms that C-5 has a X (1)Sigma(+)(g) linear isomer of prominent stability and, at least, three minimum energy structures showing singlet electronic ground states. Two of them are cyclic and one has a nonplanar geometry. Vertical and adiabatic electronic transitions and vibrational spectroscopic parameters are determined for the most stable linear isomer using multiconfigurational second order perturbation theory (CASPT2) using an active space containing 12 valence orbitals with 12 active electrons and extended ANO-type basis sets. The infrared spectrum has been analyzed from an anharmonic force field derived form the local surface, determined from the energies of a grid of 1350 geometries. The force field includes four coupling terms. The CASPT2 band center position of the nu(7)(pi(u)) anharmonic fundamental has been calculated to be at 102 cm(-1), which validates the assignment to C-5 of the pattern of bands centered at 102 cm(-1) observed with the ISO telescope. (C) 2007 American Institute of Physics. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
127
issue
15
publisher
American Institute of Physics
external identifiers
  • wos:000250295900036
  • scopus:39449095235
ISSN
0021-9606
DOI
10.1063/1.2759206
language
English
LU publication?
yes
id
067d900b-5ce2-4eb2-b156-669d1cb62756 (old id 653106)
alternative location
http://link.aip.org/link/?JCPSA6/127/154318/1
date added to LUP
2007-12-15 13:57:56
date last changed
2017-03-26 03:27:13
@article{067d900b-5ce2-4eb2-b156-669d1cb62756,
  abstract     = {In this paper, the structure and spectroscopic parameters of the C-5 cluster are determined using multiconfigurational quantum chemical methods as implemented in the MOLCAS software. A number of spectroscopic properties (band center positions, l-doubling parameters, and rotational constants) have been characterized. From the new results, the assignments of previous astrophysical observations [J. Goicoechea , Astrophys. J. 609, 225 (2004)] are discussed. A detailed exploration of the global potential energy surface confirms that C-5 has a X (1)Sigma(+)(g) linear isomer of prominent stability and, at least, three minimum energy structures showing singlet electronic ground states. Two of them are cyclic and one has a nonplanar geometry. Vertical and adiabatic electronic transitions and vibrational spectroscopic parameters are determined for the most stable linear isomer using multiconfigurational second order perturbation theory (CASPT2) using an active space containing 12 valence orbitals with 12 active electrons and extended ANO-type basis sets. The infrared spectrum has been analyzed from an anharmonic force field derived form the local surface, determined from the energies of a grid of 1350 geometries. The force field includes four coupling terms. The CASPT2 band center position of the nu(7)(pi(u)) anharmonic fundamental has been calculated to be at 102 cm(-1), which validates the assignment to C-5 of the pattern of bands centered at 102 cm(-1) observed with the ISO telescope. (C) 2007 American Institute of Physics.},
  author       = {Masso, H. and Veryazov, Valera and Malmqvist, Per-Åke and Roos, Björn and Senent, M. L.},
  issn         = {0021-9606},
  language     = {eng},
  number       = {15},
  publisher    = {American Institute of Physics},
  series       = {Journal of Chemical Physics},
  title        = {Ab initio characterization of C-5},
  url          = {http://dx.doi.org/10.1063/1.2759206},
  volume       = {127},
  year         = {2007},
}