A new open-framework indium sulfide ([In12S24H2](10-)) constructed from pentasupertetrahedral sulfide clusters ([ln(8)S(17)H],(9-)P1) and supertetrahedral sulfide clusters ([In4S10H],(7-) T2) has been prepared through hydrothermal synthesis. Unlike previously reported P1 clusters that require divalent metal cations, the P1 cluster reported here consists of only trivalent ions (ln(3+)) and is the only known example of tetrahedral clusters with a core sulfur site bonded to four trivalent ions. Each P1 cluster is joined to three T2 clusters (vice versa) to form an infinite twodimensional sheet stacked along the crystallographic c-axis. In contrast with known three- dimensional open-framework indium sulfides in which locations of extraframework amines are rarely known due to disorder, structure-directing amine molecules are much less disordered as a result of host - guest N - H center dot center dot center dot S hydrogen bonding. The UV - vis diffuse reflectance spectrum shows that this material is a wide band gap semiconductor.