MULTILAYER RELAXATION OF RH(311)

The multilayer relaxation of the Rh(311) surface was investigated by means of LEED structure determination both for vertical and surface parallel (registry) relaxations. Excellent agreement between experimental and calculated spectra could be achieved mirrored by a minimum Pendry R-factor R = 0.174. The first three layer spacings are oscillatorily relaxed by DELTA-d12/d0 = -14.5 +/- 1.8%, DELTA-d23/d0 = + 4.9 +/- 2.0% and DELTA-d34/d0 = -1.0 +/- 2.0%. There seems to be a coherent registry shift of the first two layers by DELTA-s = 0.03 +/- 0.07 A which, however, is within the error limit of the structure determination. Moreover, an energy dependent inner potential is detected. The results are discussed in comparison to equivalent surfaces of other materials as well as for the less open surfaces of rhodium.