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 KN3 (Materials Project id mp-636056)

         9        5        4        0        0        0  
         5        9        4        0        0        0  
         4        4       40        0        0        0  
         0        0        0       -1        0        0  
         0        0        0        0       -1        0  
         0        0        0        0        0        1  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 9.3333 GPaEV = 7.6364 GPaGV = 2.8 GPaνV = 0.36364
ReussKR = 6.7692 GPaER = -101.54 GPaGR = -12.692 GPaνR = 3
HillKH = 8.0513 GPaEH = -18.659 GPaGH = -4.9462 GPaνH = 0.88626

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-1 GPa -1 GPa 1 GPa 4 GPa 12.823 GPa 41.177 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.