title: Low-temperature phase of hexaguanidinium hepta-molybdate monohydrate.
abstract: The crystal structure of the title compound, [C(NH(2))(3)](6)[Mo(7)O(24)]·H(2)O, previously determined at room temperature in the monoclinic space group C2/c from Weissenberg techniques [Don & Weakley (1981 ▶). Acta Cryst. B37, 451-453], has been redetermined from low-temperature single-crystal data in the monoclinic space group P2(1)/c. The asymmetric unit contains one hepta-molybdate anion, six guanidinium cations and one water mol-ecule of hydration. The anions and cations are linked by an extensive network of N-H⋯O hydrogen bonds.
authors.affiliation: School of Engineering and Science, Jacobs University Bremen, PO Box 750561, 28725 Bremen, Germany.
authors.forename: Santiago
authors.initials: S
authors.lastname: Reinoso
authors.forename: Michael H
authors.initials: MH
authors.lastname: Dickman
authors.forename: Antonia
authors.initials: A
authors.lastname: Praetorius
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kortz