Cd3As2 is Centrosymmetric

TL;DR

This paper confirms that Cd3As2 has a centrosymmetric crystal structure, correcting previous misconceptions and providing detailed structural and electronic analysis based on modern crystallography tools.

Contribution

It revises the crystal symmetry classification of Cd3As2 using advanced analysis, correcting past errors and offering detailed structural and electronic data for future research.

Findings

Cd3As2 is confirmed to be centrosymmetric.

Previous noncentrosymmetric classification was due to an analytical error.

Provides detailed structural and electronic structure data.

Abstract

This is a revised version of a manuscript that was originally posted here in February of 2014. It has been accepted at the journal Inorganic Chemistry after reviews that included those of two crystallographers who made sure all the t's were crossed and the i's were dotted. The old work (from 1968) that said that Cd3As2 was noncentrosymmetric was mistaken, with the authors of that study making a type of error that in the 1980s became infamous in crystallography. As a result of the increased scrutiny of the issue of centrosymmetricity of the 1980's, there are now much better analysis tools to resolve the issue fully, and its important to understand that not just our crystals are centrosymmetric, even the old guy's crystals were centrosymmetric (and by implication everyone's are). There is no shame in having made that error back in the day and those authors would not find the current centrosymmetric result controversial; their paper is excellent in all other aspects. This manuscript describes how the structure is determined, explains the structure schematically, calculates the electronic structure based on the correct centrosymmetric crystal structure, and gives the structural details that should be used for future analysis and modeling.