# A DFT study of mechanical properties of hcp Rhenium

## TL;DR

This study uses density-functional theory to analyze the structural, elastic, and thermodynamic properties of hcp Rhenium, revealing its high bulk modulus but relatively low hardness compared to diamond.

## Contribution

First comprehensive DFT analysis of hcp Rhenium's mechanical and thermodynamic properties including elastic constants and hardness predictions.

## Key findings

- Re has a high bulk modulus similar to diamond.
- Re's Vicker's hardness is five times less than diamond.
- The lattice constant matches experimental and theoretical data.

## Abstract

In the present paper, hcp Re was investigated in terms of its structural, elastic, mechanical and thermodynamic properties using density-functional theory (DFT). The local density approximation was employed for the exchange-correlation potential together with spin-orbit coupling. The computed lattice constant was found to be in agreement with the available experimental and theoretical results. The elastic constants were also calculated and used to determine mechanical properties like Young's modulus (Y), the shear modulus (G), Poisson's ratio (n) and Vicker's hardness. From thermodynamic investigations, the heat capacity and entropy were also predicted. Although the predicted bulk modulus of Re is comparable to that of a diamond, the Vicker's hardness was found to be five times less than that of a diamond. Hence, Re is a typical solid with high bulk modulus but low Vicker's hardness.