PKU-10, a germanate with the formula [(CH3)(4)N](3)Ge11O19(OH)(9), is synthesized under hydrothermal conditions, and its structure is determined by single-crystal X-ray diffraction data. PKU-10 possesses 3D intersected 13-ring channels and presents a new 6-connectedness linkage mode of the Ge-7 cluster, (TPO)-P-3-O-2, forming a pcu topological network. Each Ge-7 cluster is, in fact, surrounded by eight Ge-7 clusters in a nearly perfect cube because the hydrogen bonds between Ge-7 clusters are also taken into account. The structure-directing agent tetramethylammonium (TMA(+)) ions, locating in the channels, can be partially exchanged by Li+ with retention of the germanate framework. The germanate framework collapses with decomposition of the TMA(+) ions at temperatures higher than 240 degrees C.