Silicon disulphide and silicon diselenide: a reinvestigation

Abstract

SiS2 and SiSe 2 are orthorhombic and isostructural, Ibam, with a = 9.583 (3), b = 5.614 (2), c = 5.547 (2),A,, V = 298.4 A 3, Z = 4, D x = 2.052 Mg m -3 at 293 K, a = 9.545(3), b = 5.564(2), c = 5.552 (2) A, V= 294.9 A 3, D x = 2.077 Mg m -3 at 138 K for SiS 2, and a = 9.669 (3), b = 5.998 (2), c = 5.851 (2) A, V = 339.3/k 3, Z = 4, D x = 3.640 Mg m -3 at 293K, a= 9.619 (3),b=5.989(2),c=5.851(2) .A, V = 337.1/~3, Dx = 3.665 Mg m -3 at 138 K for SiSe 2. The refinements-at 138 K (SiS 2) and 293 K (SiSe2) confirm the known structure types with some significant changes in cell dimensions and atomic coordinates. Final R factors for SiS2 (SiSe 2) are 0.041 (0.018) for 200 (253) observed reflexions. Within the chains of edge-sharing SiS~ (SiSe4) tetrahedra, the SiS (SiSe) bond lengths are 2.133 (I)A [2.275 (1)A], the S-Si-S (Se-Si-Se) bond angles in the planar fourmembered Si2S / (Si2Se2) rings are 98.8 (l)° [ 100.0 (1)°l.

Structural Classification of Quasi-One-Dimensional Ternary Nitrides

“…These tetrahedral chains are in a similar arrangement to those found in SiS2 [46]. In SiS2, edge-sharing [SiS ⁄ ] units are hexagonally packed and held together by van der Waals interactions [46,47]. The chains in Li3FeN2 are also arranged with hexagonal rod-packing, but are separated by lithium-centred tetrahedra (Figure 2).…”

“…The FeN4 tetrahedra are ordered in such a way as to result in chains of edge-sharing [FeN ⁄ ] tetrahedra connected along [001]. These tetrahedral chains are in a similar arrangement to those found in SiS2 [46]. In SiS2, edge-sharing [SiS ⁄ ] units are hexagonally packed and held together by van der Waals interactions [46,47].…”

“…Several of the transition metal compounds form structures in both these groups. In the Li-Fe-N system, solid solutions of the compositions Li 1-x [46,47]. The chains in Li 3 FeN 2 are also arranged with hexagonal rod-packing, but are separated by lithium-centred tetrahedra (Figure 2).…”

Prediction of a metastable phase of silicon in theIbamstructure

“…1, has distorted tetrahedral bonding with the interesting feature of having four-fold rings. These four-fold rings are connected in a chain-like manner, similar to that found in SiS 2 and SiSe 2 which also take the Ibam structure 27 . The presence of only even-membered rings opens up the possibility of this structure forming in III-V semiconductors because of the absence of energetically unfavorable same-species bonds.…”

A Novel Effect of CO2 Laser Induced Piezoelectricity in Ag2Ga2SiS6 Chalcogenide Crystals

“…Following the second coordination of sulfur [14], the compounds AgGaS 2 [15], Ag 2 Ga 2 SiS 6 [13] and SiS 2 [16] possess similar anionic sub-lattices in the form of cubooctahedra. Within the mentioned anionic sub-lattice, the cationic atoms occupy the equivalence tetrahedral voids.…”