Mechanochemical synthesis and crystal structure evaluation of Na₂ZnSnS₄

Abstract

Phase‐pure and highly crystalline Na2ZnSnS4 was prepared via a mechanochemical synthesis route. It crystallizes in the kesterite‐type structure. The unusual large Debye‐Waller factors of the sodium atoms were analyzed in detail, respecting also group‐theoretical aspects. The results point to the existence of static disorder, mainly to the presence of various patterns of sodium ordering on a local scale. This is confirmed by quantum‐chemical calculations at hybrid density‐functional theory level. The dynamic atomic displacements due to phonons are much smaller than the observed Debye‐Waller factors.

BaCu2SiS4: A New Member of the AIIBI2MIVQ4 Chalcogenide Family with a Chiral Crystal Structure

“…SCXRD revealed that BaCu 2 SiS 4 crystallizes in the trigonal, noncentrosymmetric, and chiral space group P3 2 21. The threedimensional structure consists of corner-sharing [CuS 4 ] and [SiS 4 ] tetrahedra that propagate as a helix, creating channels along the [100], [010], and [110] directions (Figure 2). Ba atoms are located in these channels.…”