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 WS2 (Materials Project id mp-224)

       196       43       -1        0        0        0  
        43      196       -1        0        0        0  
        -1       -1        0        0        0        0  
         0        0        0        1        0        0  
         0        0        0        0        1        0  
         0        0        0        0        0       76  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 52.667 GPaEV = 93.838 GPaGV = 39 GPaνV = 0.20305
ReussKR = -0.0082305 GPaER = -0.041844 GPaGR = -0.032057 GPaνR = -0.34734
HillKH = 26.329 GPaEH = 46.886 GPaGH = 19.484 GPaνH = 0.2032

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-0.0083679 GPa 1 GPa 1 GPa 76 GPa 153 GPa 239.01 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.