The smallest unit cell consistent with electron-diffraction patterns of the 8th-order reconstructed Ge(111) surface was shown to be a c(2 x 8) cell, rather than the commonly assumed 2 x 8 cell. A structural model which was consistent with the observed electron diffraction data was proposed.

New c-2x8 Unit Cell for the Ge(111) Surface. D.J.Chadi, C.Chiang: Physical Review B, 1981, 23, 1843-6