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 Rb2CoF4 (Materials Project id mp-559959)

       -31      135       23        0        0        0  
       135      -31       23        0        0        0  
        23       23       66        0        0        0  
         0        0        0       13        0        0  
         0        0        0        0       13        0  
         0        0        0        0        0       25  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 40.667 GPaEV = -4.8638 GPaGV = -1.6 GPaνV = 0.51993
ReussKR = 40.319 GPaER = 56.57 GPaGR = 22.339 GPaνR = 0.26616
HillKH = 40.493 GPaEH = 28.662 GPaGH = 10.37 GPaνH = 0.38203

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-166 GPa 13 GPa 13 GPa 25 GPa 47.33 GPa 122.67 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.