The absorption of atomic H in the high-coverage regime was investigated. It was found that the surface, under these conditions, underwent reconstruction into the fairly rare pgg or p4g symmetry. The reconstruction was found to coincide with a new high-resolution electron energy-loss spectroscopic feature, in addition to the one which was present at low coverages and which was attributed to H in a hollow site. The new loss feature was attributed to H which was present at a bridge-bonded site.

I.Chorkendorff, P.B.Rasmussen: Journal of Physics - Condensed Matter, 1991, 3[SA], S107-10