VIBRATIONAL-SPECTRA OF HEXA-ATOMIC SILICON-CARBON CLUSTERS .1. LINEARSIC4SI

Fourier transform infrared measurements on the spectra of the products of the evaporation of silicon/carbon mixtures trapped in Ar at simila r to 10 K, combined with the results of ab initio Calculations publish ed earlier, and density functional theory (DFT) calculations carried o ut in the present work, have resulted in the detection for the first t ime of the linear SiC4Si cluster. Two vibrational fundamentals have be en assigned, the C=C stretching mode nu(4)(sigma(u))= 1807.4 cm(-1), a nd the Si-C stretching mode nu(5)(sigma(u))=719.1 cm(-1). The observed frequencies, relative intensities, and isotopic shifts are in very go od agreement with the results of the DFT calculations and confirm the previously predicted, linear symmetric geometry for the ground state o f SiC4Si. (C) 1997 American Institute of Physics.