X-ray diffraction analysis reveals the thiogermanic acid H4Ge4S10 possesses discrete adamantane-like Ge4S104- complex anions. Each thioanion is composed of four corner shared GeS2.5- tetrahedral units. Crystals were grown from anhydrous liquid hydrogen sulfide reactions with glassy germanium sulfide at room temperature. The crystal structure was solved and refined from single crystal diffractometer data (Mo Kalpha radiation) obtained at 173 K. H4Ge4S10 is triclinic, centrosymmetric space group P1, with a = 8.621(4) Angstrom, b = 9.899(4) Angstrom, c = 10.009(4) Angstrom, alpha = 85.963-(7)degrees, beta = 64.714(7)degrees, gamma = 89.501(8)degrees, and Z= 2. Average bridging and terminal (d) over bar (Ge-S) distances are 2.229 and 2.206 Angstrom, respectively. Vibrational mode assignments are reported from Raman scattering and IR absorption spectra of polycrystalline samples. The v(s)(Ge-S-Ge) and v(s)(Ge-S-) stretching modes are observed at 354 and 405 cm(-1), respectively.