ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Using Möller–Plesset second-order perturbation theory (MP2) for the geometry optimizations, we have examined various structural possibilities for the Si4C cluster. The energies of the MP2-optimized structures have been calculated using singles and doubles coupled cluster (CCSD) theory and the CCSD (T) method. The structure of lowest energy is a C3V symmetric trigonal pyramid made from four silicons and one carbon atom in a face capping position. Very close in energy (around 5 kcal/mol) lies an isomer with C2V symmetry, resembling the pyramid of the previous structure but with the carbon atom in an edge capping position this time. Both of these structures are closely related to the Si5 ground state structure. Planar and linear structures analogous to C5 and C4 lie higher in energy and they are transition states in most of the cases examined. To help future experimental tests of our present results, we have computed, at the MP2-level, the harmonic frequencies, infrared intensities, and isotopic shifts for the two lowest-lying isomers. Dipole moments and 1s core electron energy shifts are also given. The building up principle we have recently suggested from a study of the Si3C3 clusters is found to be fully operative for the Si4C cluster. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.471004
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