The self-assembly of [BzEtPy] + ([BzEtPy] + =benzyl-4-ethylpyridinium) cation and the [Ni(mnt) 2 ] − (mnt 2− =maleonitriledithiolate) anion results in the forming of a new molecular solid [BzEtPy][Ni(mnt) 2 ](1), in which the anions and cations stack into columns and the Ni(III) ions form a 1D zigzag alternating chain through Ni···S and π···π interactions between [Ni(mnt) 2 ] − anions with the Ni···Ni distances of 3.886Å and 4.781Å, and the four columns of cations create cubic-like large channel in which the [Ni(mnt) 2 ] − columns are located. Magnetic susceptibility measurements show that 1 exhibits a spin gap transition around 90K.