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 BaSi2(NO)2 (Materials Project id mp-6764)

       152       27       50        0        0        0  
        27      211       50        0        0        0  
        50       50      266        0        0        0  
         0        0        0       61        0        0  
         0        0        0        0       97        0  
         0        0        0        0        0      -10  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 98.111 GPaEV = 155.81 GPaGV = 63.067 GPaνV = 0.23531
ReussKR = 91.542 GPaER = -502.01 GPaGR = -103.98 GPaνR = 1.414
HillKH = 94.826 GPaEH = -66.123 GPaGH = -20.456 GPaνH = 0.61622

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-10 GPa 61 GPa 97 GPa 132.17 GPa 181.52 GPa 315.31 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.