SYNTAX : FACB name1 name2 name3 M-H_dist1 M-H_dist2 M-H_dist3 sig1 sig2 sig3 ni
As for the TERM and EDGE instructions, this causes a search for a hydride which bridges the face defined by the metal atoms given by name1, atom name2 and name3. The required M-H distances in Å are as above. Default settings of M-H_dist, sig and ni are 1.95, 0.05 and 250 respectively. If M-Hdist2, M-Hdist3 etc are omitted then all distances are assumed equal.