HoRu2Si2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho3+ is bonded in a 8-coordinate geometry to eight equivalent Si4- atoms. All Ho–Si bond lengths are 3.21 Å. Ru+2.50+ is bonded to four equivalent Si4- atoms to form a mixture of edge and corner-sharing RuSi4 tetrahedra. All Ru–Si bond lengths are 2.38 Å. Si4- is bonded in a 4-coordinate geometry to four equivalent Ho3+ and four equivalent Ru+2.50+ atoms.