1. Unilever Research and Development, Port Sunlight Laboratory, Quarry Road East, Bebington, Wirral CH63 3JW, U.K.
2. ISIS Facility, STFC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 OQX, U.K.
3. Institut Laue Langevin, F-38042 Grenoble, France