A vibrational study of the polymer electrolyte compound poly(ethylene oxide)(6):LiAsF6 is reported. A symmetry-based factor group correlation method is applied to interpret the observed bands. The Raman and infrared spectra of the compound are consistent with the reported crystal structure. The nu (1) mode, which appears at 685 cm(-1), identifies the anions as being "spectroscopically free". Multiple bands in the nu (3) spectral region are interpreted as resulting from the dynamical coupling of the four AsF6- anions in the unit cell. The rho (CH2) region shows multiple bands that arise from the complex conformations of the polymer backbone.