title: A new whitlockite, Ca8.42Na1.16V(PO4)7.
abstract: Single crystals of a new complex phosphate, calcium sodium vanadium phosphate, Ca8.42Na1.16V(PO4)7, have been grown from a melt under an inert atmosphere. The crystal structure has rhombohedral (R3c) symmetry and belongs to the whitlockite structure type. Vanadium(III) ions occupy nearly regular octahedral sites (M5 with 3 point symmetry), which share corners with six PO4 tetrahedra to form isolated units. The calcium ions occupy eight- and nine-coordinated sites. The sodium ions partially occupy one octahedral position and share one nine-coordinated position with a Ca atom.
authors.affiliation: Department of Chemistry, Moscow State University, 119992 Moscow, Russian Federation.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Tsirlin
authors.forename: Evgeny V
authors.initials: EV
authors.lastname: Dikarev
authors.forename: Roman V
authors.initials: RV
authors.lastname: Shpanchenko
authors.forename: Evgeny V
authors.initials: EV
authors.lastname: Antipov