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 WSe2 (Materials Project id mp-1821)

       158       31       -0        0        0        0  
        31      158       -0        0        0        0  
        -0       -0       -2        0        0        0  
         0        0        0        1        0        0  
         0        0        0        0        1        0  
         0        0        0        0        0       64  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 41.778 GPaEV = 76.601 GPaGV = 32.067 GPaνV = 0.19441
ReussKR = -2.0432 GPaER = 27.148 GPaGR = 3.6543 GPaνR = 2.7144
HillKH = 19.867 GPaEH = 41.227 GPaGH = 17.861 GPaνH = 0.15414

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-2 GPa 1 GPa 1 GPa 64 GPa 127 GPa 189 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.