Abstract
The tight atomic packing generally exhibited by alloys and intermetallics can create the impression of their being composed of hard spheres arranged to maximize their density. As such, the atomic size factor has historically been central to explanations of the structural chemistry of these systems. However, the role atomic size plays structurally has traditionally been inferred from empirical considerations. The recently developed DFT-Chemical Pressure (CP) analysis has opened a path to investigating these effects with theory. In this article, we provide a step-by-step tutorial on the DFT-CP method for non-specialists, along with advances in the approach that broaden its applicability. A new version of the CP software package is introduced, which features an interactive system that guides the user in preparing the necessary electronic structure data and generating the CP scheme, with the results being readily visualized with a web browser (and easily incorporated into websites). For demonstration purposes, we investigate the origins of the crystal structure of K3Au5Tl, which represents an intergrowth of Laves and Zintl phase domains. Here, CP analysis reveals that the intergrowth is supported by complementary CP features of NaTl-type KTl and MgCu2-type KAu2 phases. In this way, K3Au5Tl exemplifies how CP effects can drive the merging for geometrical motifs derived from different families of intermetallics through a mechanism referred to as epitaxial stabilization.
Highlights
Conflict between electronic and steric factors is a theme that pervades chemistry as a field
To explore the electronic factor, one can anticipate preferred electron counts based on the features of density of states (DOS) curves [1,2], quantify interaction strengths with the crystal orbital Hamiltonian population (COHP) analysis [3,4,5], detect regions of space where individual electron pairs tend to predominate with the electron localization function (ELF) [6,7,8], and generate localized orbitals from the wavefunctions using Wannier analysis [9,10,11,12,13] or the reverse approximation Molecular Orbital approach [14,15]
We have provided a step-by-step guide to the creation and interpretation of the Chemical Pressure (CP) schemes of solid-state structures, with the packing contributions to the stability of
Summary
Conflict between electronic and steric factors is a theme that pervades chemistry as a field. To explore the electronic factor, one can anticipate preferred electron counts based on the features of density of states (DOS) curves [1,2], quantify interaction strengths with the crystal orbital Hamiltonian population (COHP) analysis [3,4,5], detect regions of space where individual electron pairs tend to predominate with the electron localization function (ELF) [6,7,8], and generate localized orbitals from the wavefunctions using Wannier analysis [9,10,11,12,13] or the reverse approximation Molecular Orbital (raMO) approach [14,15] Together, these and other methods provide a powerful theoretical toolbox for analyzing the ways in which the valence electrons of a system influence the stability of different crystal structure arrangements. Laves phases represented by the NaTl and MgCu2 structure types, respectively
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
