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-1025571)

       128       25       -4        0        0        0  
        25      128       -4        0        0        0  
        -4       -4        6        0        0        0  
         0        0        0       -4        0        0  
         0        0        0        0       -4        0  
         0        0        0        0        0       51  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 32.889 GPaEV = 59.711 GPaGV = 24.933 GPaνV = 0.19741
ReussKR = 4.895 GPaER = 146.73 GPaGR = -20.986 GPaνR = -4.4958
HillKH = 18.892 GPaEH = 5.7213 GPaGH = 1.9735 GPaνH = 0.44953

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-4 GPa -4 GPa 5.7826 GPa 51 GPa 103 GPa 153.22 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.