(Ru)2(Ru2H)2(CO)17 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of thirty-four formaldehyde molecules, four ruthenium molecules, and two Ru2H clusters. In each Ru2H cluster, there are four inequivalent Ru2+ sites. In the first Ru2+ site, Ru2+ is bonded in a distorted single-bond geometry to one H1+ atom. The Ru?H bond length is 1.87 �. In the second Ru2+ site, Ru2+ is bonded in a distorted single-bond geometry to one H1+ atom. The Ru?H bond length is 1.85 �. In the third Ru2+ site, Ru2+ is bonded in a 2-coordinate geometry to two H1+ atoms. Both Ru?H bond lengths are 1.97 �. In the fourth Ru2+ site, Ru2+ is bonded in a distorted L-shaped geometry to two H1+ atoms. There is one shorter (1.92 �) and one longer (1.95 �) Ru?H bond length. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a trigonal non-coplanar geometry to three Ru2+ atoms. In the second H1+ site, H1+ is bonded in a trigonal non-coplanar geometry to three Ru2+ atoms.