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 BF3 (Materials Project id mp-558149)

        14       -1        3        0       -2        0  
        -1       14        4        0        0        0  
         3        4        8        0        1        0  
         0        0        0        3        0       -1  
        -2        0        1        0        3        0  
         0        0        0       -1        0        0  

Average properties

Averaging schemeBulk modulusYoung's modulusShear modulusPoisson's ratio
VoigtKV = 5.3333 GPaEV = 8 GPaGV = 3.2 GPaνV = 0.25
ReussKR = 5.2736 GPaER = -9.1921 GPaGR = -2.5669 GPaνR = 0.79051
HillKH = 5.3035 GPaEH = 0.93114 GPaGH = 0.31656 GPaνH = 0.47074

Eigenvalues of the stiffness matrix

λ1 λ2 λ3 λ4 λ5 λ6
-0.30278 GPa 2.0102 GPa 3.3028 GPa 5.6792 GPa 15.141 GPa 16.169 GPa
Stiffness matrix is not definite positive, crystal is mechanically unstable
No further analysis will be performed.