Electro-oxidation of a solution of [AcrH][Ni(dmit)(2)] (AcrH = acridinium; dmit = 2-thioxo-1,3-dithiole-4,5-dithiolate) yields black crystals of [AcrH][Ni(dmit)(2)](3) (1). Black crystals of [PheH][Ni(dmit)(2)](3) (2) (PheH = phenazinium) are obtained by slow interdiffusion of solutions of PheHBF(4) and [Bu4N][Ni(dmit)(2)]. Crystals of 1 are monoclinic, of space group C2/c, with a = 39.124(3) Angstrom, b = 6.4777(5) Angstrom, c = 20.621(1) Angstrom, beta = 110.55(1)degrees, and Z = 4. Crystals of 2 are triclinic, of space group P (1) over bar, with a = 5.7795(6) Angstrom, b = 12.056(1) Angstrom, c = 19.041(1) Angstrom, alpha = 71.98(1)degrees, beta = 89.47(1)degrees, gamma = 77.99(1)degrees, and Z = 1. The crystal structures of the two compounds are very different. In compound 2, regular stacks of slightly dimerized Ni(dmit)(2) units are found and short S ... S interactions are found in two dimensions. Compound 1, however, shows stacks built from trimers of Ni(dmit)(2) units, which are rotated 30 degrees toward each other, forming a ''spanning overlapping mode''. Short S ... S interactions are found in all three dimensions. Compound 1 shows a room-temperature conductivity of 45 S.cm(-1) and metallic conductivity behavior from room temperature down to 0.4 K. No superconductivity is observed at high pressures of 8 and 13 kbar. Compound 2 shows a room-temperature conductivity of 4 S.cm(-1) and semimetallic conductivity behavior from room temperature down to 100 K. The measured conductivity behaviors are in good agreement with the results obtained from band-structure calculations according to a tight-binding model and including Coulomb repulsion.