RbFeS2 crystallizes in the monoclinic C2/c space group. Rb(1) is bonded to eight equivalent S(1) atoms to form distorted RbS8 hexagonal bipyramids that share corners with four equivalent Rb(1)S8 hexagonal bipyramids, corners with six equivalent Fe(1)S4 tetrahedra, edges with six equivalent Rb(1)S8 hexagonal bipyramids, edges with five equivalent Fe(1)S4 tetrahedra, and faces with two equivalent Rb(1)S8 hexagonal bipyramids. Fe(1) is bonded to four equivalent S(1) atoms to form FeS4 tetrahedra that share corners with six equivalent Rb(1)S8 hexagonal bipyramids, edges with five equivalent Rb(1)S8 hexagonal bipyramids, and edges with two equivalent Fe(1)S4 tetrahedra. S(1) is bonded in a 6-coordinate geometry to four equivalent Rb(1) and two equivalent Fe(1) atoms.
RbFeS2 crystallizes in the monoclinic C2/c space group. Rb(1) is bonded to eight equivalent S(1) atoms to form distorted RbS8 hexagonal bipyramids that share corners with four equivalent Rb(1)S8 hexagonal bipyramids, corners with six equivalent Fe(1)S4 tetrahedra, edges with six equivalent Rb(1)S8 hexagonal bipyramids, edges with five equivalent Fe(1)S4 tetrahedra, and faces with two equivalent Rb(1)S8 hexagonal bipyramids. There are a spread of Rb(1)-S(1) bond distances ranging from 3.44-3.52 Å. Fe(1) is bonded to four equivalent S(1) atoms to form FeS4 tetrahedra that share corners with six equivalent Rb(1)S8 hexagonal bipyramids, edges with five equivalent Rb(1)S8 hexagonal bipyramids, and edges with two equivalent Fe(1)S4 tetrahedra. There are two shorter (2.20 Å) and two longer (2.21 Å) Fe(1)-S(1) bond lengths. S(1) is bonded in a 6-coordinate geometry to four equivalent Rb(1) and two equivalent Fe(1) atoms.