Analysis of the Rotational Levels of SiC2

✍ Scribed by L.H. Coudert

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 801 KB
• Volume: 160
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1993.1170

✦ Synopsis

In the (\mathrm{T})-shaped (\mathrm{SiC}{2}) molecule, there is experimental evidence that the (C{2}) fragment is bound to the silicium atom by an ionic essentially nondirectional bond, and thus can rotate within the molecule. The (\nu_{3}) mode, corresponding to this internal rotation, is, therefore, a large-amplitude motion. In an attempt to calculate the rovibrational energy levels of the (\mathrm{SiC}{2}) molecule, a formalism is derived in which this (v{3}) mode is treated as a large-amplitude motion. In this formalism, the strong dependence of the inverse moment of inertia tensor on the angle of internal rotation, the Coriolis coupling between the large amplitude motion and the overall rotation, and the potential barrier hindering the internal rotation are accounted for. This formalism is used to carry out analyses of the microwave data of (\mathrm{SiC}{2}) within the ground vibrational state and within the first excited vibrational state of the (v{3}) mode, (v_{3}=1). For both vibrational states, which are fitted separately. more satisfactory results are obtained than with a standard Watson-type Hamiltonian. c: 1493 Academic Press. Inc