We argue that the experimental evidence of Eberhard, Plummer, Horn, and Erskine for the symmetry of the surface states they have found at the corner of the rectangular two-dimensional Brillouin zone of Ni(110) seems to favor their arising from bulk $Q_1$ (mainly $d$-like) bands [rather than $Q_2$ (mainly $d$-like) bands as they claim]. This would be in agreement with the symmetry given by thin-film band calculations.

• Received 29 August 1980

DOI:https://doi.org/10.1103/PhysRevB.23.6805