Observation of high-frequency vibrational gap modes for KI:Cl- and KI:Br- A. R. Grant, A. J. Sievers, M. J. L. Sangster and D. Strauch Europhys. Lett., 34 1 (1996) 63-68 Published online: 01 September 2002 DOI: 10.1209/epl/i1996-00416-x