Coloring in the ZrBeSi-type structure

Abstract

The ZrBeSi type is a superstructure variant of the aristotype AlB2 with an ordering of the beryllium and silicon atoms on the boron network. Every other layer of Be3Si3 hexagons is rotated by 60°, leading to an ABAB stacking sequence and a sandwich-like coordination of zirconium by two Be3Si3 hexagons. The ZrBeSi type shows a pronounced coloring on its three crystallographic sites. Among the numerous compounds are electron-precise Zintl phases in the field of tetrelides, pnictides and chalcogenides, selenide hydrides and fluorides as well as intermetallic compounds. A variety of element combinations leads to distinctly differing c/a ratios and different bonding patterns. Several compounds are rather isopointal than isotypic. The present work focuses on a crystal chemical description of selected ZrBeSi related compounds and the results of theoretical studies for evaluating the bonding peculiarities. From quantum theory (DFT) based investigations, the trends of charge transfer according to Bader’s AIM theory have been established. These are in general agreement with the course of the electronegativities. For the prototype ZrBeSi, the main characteristics are illustrated through the electron localization function, manifesting the sp2-like planar hybridization for the silicon atoms. The site-projected densities of states PDOS of a series of compounds underline a continuous trend from metallic (e.g. ZrBeSi) to semi-conducting (e.g. LiBC) compounds in agreement with the observed electron exchanges.

The Structural, Mechanical, Lattice Dynamical, and Thermal Properties of 3D Dirac Semimetals BaXBi (X=Cu, Ag, Au) from First‐Principles Calculations

“…[ 8 ] Second is work related to the ZrBeSi‐type intermetallic compounds, where the position (2a) (0, 0, 0) of the crystal are occupied by less electronegative atoms. [ 28 ]…”

“…[8] Second is work related to the ZrBeSi-type intermetallic compounds, where the position (2a) (0, 0, 0) of the crystal are occupied by less electronegative atoms. [28] Next, Θ D (Debye temperature) is calculated. It is strongly correlated with melting point, where Θ D is about 30-50% of the melting temperature.…”

Equiatomic intermetallic barium compounds BaTX (T=Pd, Pt, Au; X=Mg, Zn, Cd) with TiNiSi and ZrBeSi type structure

“…The crystal chemistry of the two prototypes have repeatedly been discussed in review articles. [3,[28][29][30][31][32] Herein we exemplarily discuss the structures of BaAuMg and BaPdZn which were refined from single crystal diffraction data and focus on the peculiarities brought in by divalent magnesium and zinc.…”

“…The many crystal chemical facets and the bonding peculiarities of the ZrBeSi type structure have recently been reviewed and we refer to this overview for further details. [32] BaAuMg, BaTZn (T = Pd, Pt) and BaTCd (T = Pd, Pt, Au) add six new representatives to the family of equiatomic BaTX compounds. The coloring on the T and X positions leads to a [15] BaAuMg, CaPd 0.85 Zn 1.15 , [37] SrPdZn [16] and BaPdZn (this work).…”

Investigating the Role of Vacancies on the Thermoelectric Properties of EuCuSb‐Eu2ZnSb2 Alloys

“…[3][4][5][6][7] Compounds with the ZrBeSi-structure can form with a wide range of compositions and can incorporate large defect concentrations, making it a ripe space to explore structureproperty relationships. [8] The ZrBeSi structure (space group P6 3 /mmc) is a ternary derivative of AlB 2 (space group P6=mmm), in which the Be and Si form a planar anionic hexagonal net (i.e., honeycomb layer). [9] The Zr cations reside in 12-fold coordinated hexagonal prisms in between the anionic layers.…”