The ab initio structure determination of [(CH3)4N]2Ge4MnS10 from X-ray powder diffraction data

Abstract

The compound [(CH3)4N]2Ge4MnS10 has been synthesized hydrothermally in glass ampoules at 393 K for two days. It has been investigated by means of X-ray diffraction and thermogravimetry. It crystallizes with the tetragonal symmetry, space group I4 and unit cell parameters, a = 9.5058(6) Å and c = 14.190(2) Å (Z = 2). The crystal structure was determined ab initio from conventional X-ray powder diffraction data and refined by the Rietveld method (RF = 0.046, Rwp = 0.071). The structure of [(CH3)4N]2Ge4MnS10 consists of tetrahedra sharing apices with a space filling of the (Ge, Mn)-S framework close to 45% (8 tetrahedra (1000 Å3)−1) consistent with the low density of the material (ρobs = 2.10 g cm−3). This thiogermanate exhibits tunnels with a mean diameter of 7 Å running along the [100] and [010] directions in which the (CH3)4N+ positive counterparts are located.