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 Na2Ti2As2O (Materials Project id mp-1025360)

        69      106       28        0        0        0  
       106       69       28        0        0        0  
        28       28      103        0        0        0  
         0        0        0       27        0        0  
         0        0        0        0       27        0  
         0        0        0        0        0        3  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 62.778 GPaEV = 45.935 GPaGV = 16.667 GPaνV = 0.37805
ReussKR = 61.178 GPaER = 37.176 GPaGR = 13.289 GPaνR = 0.39872
HillKH = 61.978 GPaEH = 41.584 GPaGH = 14.978 GPaνH = 0.38818

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-37 GPa 3 GPa 27 GPa 27 GPa 85.484 GPa 192.52 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.