It was noted that the phase, of the alternation of up and down atoms along the chain, shifted at a type-B boundary between π-bonded chain-type (2 x 1) reconstructed domains on {111}. No such shift was observed at some domain boundaries in empty-state scanning tunnelling microscopic images. The absence of the shift was attributed to the domain boundary between the original Pandey chain-right reconstruction and its chain-left isomer.

Chain-Left Isomer of the π-Bonded Chain Reconstruction at the Ge{111}-2x1 Surface. H.Hirayama, N.Sugihara, K.Takayanagi: Physical Review B, 2000, 62[11], 6900-3