ELATE: Elastic tensor analysis

Welcome to ELATE, the online tool for analysis of elastic tensors, developed by Romain Gaillac and Fran├žois-Xavier Coudert at CNRS / Chimie ParisTech.
If you use the software in published results (paper, conference, etc.), please cite the corresponding paper (J. Phys. Condens. Matter, 2016, 28, 275201) and give the website URL.

ELATE is open source software. Any queries or comments are welcome at

Summary of the properties

Input: stiffness matrix (coefficients in GPa) of ZrH2 (Materials Project id mp-24155)

        81      197      197        0        0        0  
       197       81      197        0        0        0  
       197      197       81        0        0        0  
         0        0        0      -56        0        0  
         0        0        0        0      -56        0  
         0        0        0        0        0      -56  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 158.33 GPaEV = -193.54 GPaGV = -56.8 GPaνV = 0.70373
ReussKR = 158.33 GPaER = -193.48 GPaGR = -56.783 GPaνR = 0.70366
HillKH = 158.33 GPaEH = -193.51 GPaGH = -56.792 GPaνH = 0.7037

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-116 GPa -116 GPa -56 GPa -56 GPa -56 GPa 475 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.