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 SnI2 (Materials Project id mp-978846)

        34        8        8        0        0        0  
         8       29       30        0        0        0  
         8       30       29        0        0        0  
         0        0        0       24        0        0  
         0        0        0        0       12        0  
         0        0        0        0        0       12  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 20.444 GPaEV = 31.495 GPaGV = 12.667 GPaνV = 0.24324
ReussKR = 19.768 GPaER = -9.135 GPaGR = -2.8963 GPaνR = 0.57702
HillKH = 20.106 GPaEH = 13.558 GPaGH = 4.8852 GPaνH = 0.38762

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-1 GPa 12 GPa 12 GPa 24 GPa 29.64 GPa 63.36 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.