Computational discovery of new modifications in scandium oxychloride (ScOCl) using a multi‐methodological approach

Abstract

Dedicated to Professor Thomas Schleid on the occasion of his 65th birthdayScandium oxychloride (ScOCl) has recently become of interest as an advanced material with possible applications in solid oxide fuel cells, photocatalysis, and electronic devices, as are oxyhalides of various transition metals. In the present study, crystal structure prediction has been utilized to fully investigate the energy landscape of ScOCl. A multi-methodological approach has been used consisting of a combination of two search methods, where the final structure optimization has been performed on ab initio level using DFT-LDA and hybrid PBE0 functionals. The experimentally observed α-ScOCl phase has been found as well as several additional structure candidates at high pressures and/or temperatures. A successful synthesis of these novel ScOCl modifications would have the potential for extending the scientific, technological and industrial applications of ScOCl.

Crystal-Structure Prediction and Experimental Investigation of the Polymorphic Lanthanum Fluoride Selenides LaFSe and La2F4Se

“…The less favorable nf1-type shows eight neighbors for La 3+ , whereas nf2 and nf3 even exhibit coordination numbers of six and seven, which are unusually low for La 3+ cations but still known in, for example, LaN and LaP or La 2 O 2 S and La 2 O 2 Se (Figure ). Moreover, the monoclinic, tetragonal, and orthorhombic symmetry found in the so far unknown predicted nf1 to nf3 structure types, respectively, has also been reported in related known ternary lanthanum chloride selenides, lanthanum selenide sulfides, , and lanthanoid halide oxides. , This analogy might help in guiding the possible future synthesis of predicted LaFSe phases, where low-temperature and/or soft-chemistry techniques might be used. In A-LaFSe, the unique La 3+ cation is coordinated as a monocapped square antiprism with four La 3+ –F – distances of 259 pm, four La 3+ –Se 2– distances of 308 pm, and a single distance between the central cation and the selenide cap of 310 pm.…”

“…Moreover, the monoclinic, tetragonal, and orthorhombic symmetry found in the so far unknown predicted nf1 to nf3 structure types, respectively, has also been reported in related known ternary lanthanum chloride selenides, 66 lanthanum selenide sulfides, 67,68 and lanthanoid halide oxides. 69,70 This analogy might help in guiding the possible future synthesis of predicted LaFSe phases, where low-temperature and/or soft-chemistry techniques might be used. In A-LaFSe, the unique La 3+ cation is coordinated as a monocapped square antiprism with four La 3+ − F − distances of 259 pm, four La 3+ −Se 3).…”

Density Functional Theory Study of Layer-Controlled Band Gap and Strong Anisotropic Properties in ScSI Nanosheet: Implications for Photoelectric Sensor

“…The ScCl 3 monolayer can be promising as a realistic 2D solid electrolyte . Besides, the indirect band gap of a ScOCl monolayer can change to a direct band gap under uniaxial strains. , Recently, a class of material RESI (RE = rare earth) with the typical FeOCl-type structure has attracted the attention of the scientific community because of its electronic structure, magnetic properties, etc. − Among them, the Young’s moduli of ScXI (X = S, Se) monolayers show strong anisotropy, and their heterostructures can form type-I and type-II band alignments . The ScSI/borophene heterostructure can form a p-type Schottky contact .…”