Five new uranyl arsenates, Na-14[UO2)(5)(AsO4)(8)]center dot 2H(2)O (1), K-6[(UO2)(5)O-5(ASO(4))(2)] (2a), K-4[(UO2)(3)O-2(ASO(4))(2)] (2b), Rb-4[(UO2)(3)O-2(ASO(4))(2)] (3), and Cs-6[(UO2)(5)O-2(AsO4)(4)] (4), were synthesized by high-temperature, high-pressure hydrothermal reactions at about 560 degrees C and 1440 bar and were characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and photoluminescence spectroscopy. Crystal data for compound 1: triclinic, P (1) over bar, a = 7.0005(3) angstrom, b = 12.1324(4) angstrom, c = 13.7428(5) angstrom, alpha = 64.175(2)degrees, beta = 89.092(2)degrees, gamma = 85.548(2)degrees, V = 1047.26(7) angstrom(3), Z = 1, R1 = 0.0185; compound 2a: monoclinic, P2(1)/c, a = 6.8615(3) angstrom, b = 24.702(1) angstrom, c = 7.1269(3) angstrom, beta = 98.749(2)degrees, V = 1193.89(9) angstrom(3), Z = 2, R1 = 0.0225; compound 2b: monoclinic, P2(1)/c, a = 6.7852(3) angstrom, b = 17.3640(8) angstrom, c = 7.1151(3) angstrom, beta = 98.801(3)degrees, V = 828.42(6) angstrom(3), Z = 2, R1 = 0.0269; compound 3: monoclinic, P2(1)/m, a = 6.9783(3) angstrom, b = 17.4513(8) angstrom, c = 7.0867(3) angstrom, beta = 90.808(3), V = 862.94(7) angstrom(3), Z = 2, R1 = 0.0269; compound 4: triclinic, P (1) over bar, a = 7.7628(3) angstrom, b = 9.3324(4) angstrom, c = 11.9336(4) angstrom, alpha = 75.611(2)degrees, beta = 73.136(2)degrees, gamma = 86.329(2)degrees, V = 801.37(5) angstrom(3), Z = 1, R1 = 0.0336. The five compounds have layer structures consisting of uranyl square, pentagonal, and hexagonal bipyramids as well as AsO4 tetrahedra. Compound 1 contains chains of discrete uranyl square and pentagonal bipyramids, 2a contains three-polyhedron-wide ribbons of edge- and corner-sharing uranyl square and pentagonal bipyramids, 2b and 3 contain dimers of edge-shairing pentagonal bipyramids that share edges with hexagonal bipyramids to form chains, and 4 contains one-polyhedron-wide zigzag chains of edge-sharing uranyl polyhedra. The double sheet structure of 1 is new, but the chain topology has been observed in an organically templated uranyl sulfate. Compound 2b is a new geometrical isomer of the phosphuranylite group. The sheet anion topologies of 2a and 4 can be obtained by splitting the beta-U3O8-type sheet into complex chains and connecting the chains by arsenates.