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 Fe4C (Materials Project id mp-1246)

       145      159      159       12       -1       -1  
       159      145      159       -2        6       -1  
       159      159      145       -2       -1        6  
        12       -2       -2      -79        0        0  
        -1        6       -1        0      -79        0  
        -1       -1        6        0        0      -79  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 154.33 GPaEV = -168.91 GPaGV = -50.2 GPaνV = 0.68241
ReussKR = 154.48 GPaER = -43.614 GPaGR = -14.096 GPaνR = 0.54706
HillKH = 154.4 GPaEH = -103.64 GPaGH = -32.148 GPaνH = 0.61187

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-81.207 GPa-79.745 GPa-79.039 GPa-13.255 GPa-11.813 GPa 463.06 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.