Ab initio characterization of linear C3Si isomers
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Archivos
Fecha
2008-08-01
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
EDP Sciences
Nombre de Curso
Licencia CC
Licencia CC
Resumen
Aims. This paper presents an ab initio characterization of linear isomers of C3Si, which are suitable species for astrophysical detection in carbon-rich sources. Methods. By the help of multiconfigurational calculations, two linear minima are characterized, namely l-SiCCC and l-CSiCC, whose relative energy is 3.3 eV, and their electronic ground states have X-3 Sigma(-) symmetry, and their electronic spectra present a high density of electronic states at low energy. Anharmonic spectroscopic parameters are predicted for both isomers and for different isotopomers using second order perturbation theory and force fields derived form 6D-potential energy surfaces. Results. The fundamental frequencies of the IR active bendings are predicted to lie around 434 cm(-1) and 169 cm(-1) for l-SiCCC. The rotational constants (Be) are computed to be 2753.16 MHz for l-SiCCC and 3205.37 MHz for l-CSiCC. For l-SiCCC, a relatively large spin-spin constant (lambda = -0.605 cm(-1)) arises from the interaction between the ground X3S- and the lowest (1)Sigma(+) excited state, located at 0.46 eV, resulting in complex vibrational IR-band shapes, at least, when the low-frequency bendings are excited.
Notas
INDEXACIÓN: WEB OF SCIENCE.
Palabras clave
CORRELATED MOLECULAR CALCULATIONS, GAUSSIAN-BASIS SETS, LABORATORY DETECTION, ROTATIONAL SPECTRUM, INFRARED BAND, SIC3, INTERSTELLAR, GEOMETRY, C-4
Citación
ASTRONOMY & ASTROPHYSICS, Volume 486, Issue 3, Page 1047-1052
DOI
10.1051/0004-6361:200809556