Raman study of tetragonal tungsten disilicide

After a brief report of recent WSi2 Raman results on the band assignment and thermal behavior of the WSi2 lines obtained for both a single crystal and a thin film, a calculation of vibrational frequencies and normal coordinates at the zone center is presented. The first results show good agreement between observed and calculated frequencies, and confirm our previous description of vibrational modes. The corresponding force constants relative to SiSi and WSi bonds are found to be different while the bond lengths are very close. The present results will be used in future calculations at the zone boundary.