ELATE: Elastic tensor analysis

Welcome to ELATE, the online tool for analysis of elastic tensors, developed by Romain Gaillac and François-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 scheme	Bulk modulus	Young's modulus	Shear modulus	Poisson's ratio
Voigt	K_V = 32.889 GPa	E_V = 59.711 GPa	G_V = 24.933 GPa	ν_V = 0.19741
Reuss	K_R = 4.895 GPa	E_R = 146.73 GPa	G_R = -20.986 GPa	ν_R = -4.4958
Hill	K_H = 18.892 GPa	E_H = 5.7213 GPa	G_H = 1.9735 GPa	ν_H = 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.

Code version: 2020.07.26 (running on Python 3.7.2)