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 TlSn (Materials Project id mp-2556)

        83      101       66        0        0        0  
       101       83       66        0        0        0  
        66       66       73        0        0        0  
         0        0        0      -21        0        0  
         0        0        0        0      -21        0  
         0        0        0        0        0      -12  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 78.333 GPaEV = -32.645 GPaGV = -10.4 GPaνV = 0.56946
ReussKR = 71.515 GPaER = -89.927 GPaGR = -26.301 GPaνR = 0.70958
HillKH = 74.924 GPaEH = -59.946 GPaGH = -18.351 GPaνH = 0.63335

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-21 GPa -21 GPa -18 GPa -12 GPa 19.908 GPa 237.09 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.