Cyanide/isocyanide abundances in the interstellar medium – I. Theoretical spectroscopic characterization
Article first published online: 21 DEC 2011
© 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS
Monthly Notices of the Royal Astronomical Society
Volume 420, Issue 2, pages 1188–1194, February 2012
How to Cite
Senent, M. L., Dumouchel, F. and Lique, F. (2012), Cyanide/isocyanide abundances in the interstellar medium – I. Theoretical spectroscopic characterization. Monthly Notices of the Royal Astronomical Society, 420: 1188–1194. doi: 10.1111/j.1365-2966.2011.20132.x
- Issue published online: 24 JAN 2012
- Article first published online: 21 DEC 2011
- Accepted 2011 October 31. Received 2011 September 26; in original form 2011 July 22
- ISM: abundances;
- ISM: molecules
Modelling molecular abundances in the interstellar medium requires accurate molecular data. In this work, structural and spectroscopic properties of a series of metal cyanides/isocyanide species containing Na, Mg, Al and Si are calculated and compared using highly correlated ab initio calculations. The metal substitution effect on molecular properties is discussed. Isomerization pathways and transitions states are detailed.
NaCN shows three isomeric structures, one T shaped and two linear forms, whereas the remaining compounds display two linear minimum energy geometries. For the first time, NaCN secondary minima are described.
Second-order perturbation theory spectroscopic parameters are determined from an anharmonic RCCSD(T)/aug-cc-pV5Z force field. Very accurate rotational constants are calculated using a complete basis set and taking into account vibrational effects and the structure variation with core electron correlation. For l-SiCN and l-SiNC, spin–orbit parameters are also provided. Present theoretical results are compared with available experimental data attaining a good agreement.