Hello All
I’m trying to calculate the elastic constants for metals such as Fe and Al to understand the script provided in the ELASTIC_T examples folder. I modified the script slightly since I’m interested in the 3 diagonal elastic constants (C11 C22 C33). I’m facing an issue with the change_box command. Since Al or Fe are cubic crystals then you cannot change the xy yz e.t.c (as written in the manual). Therefore, i tried to change the command to deform only in x and use the volume keyword for the y and z directions and so on for the y and z directions. The estimations are not reasonable. Kindly assist me regarding the usage of this code in orthogonal crystals. How it is possible to find the other components as well C12 C23 e.t.c by deforming using the change_box command.
Regards
Hello All
I’m trying to calculate the elastic constants for metals such as Fe and Al to understand the script provided in the ELASTIC_T examples folder. I modified the script slightly since I’m interested in the 3 diagonal elastic constants (C11 C22 C33). I’m facing an issue with the change_box command. Since Al or Fe are cubic crystals then you cannot change the xy yz e.t.c (as written in the manual).
that is nonsense. you can change those parameters, you just have to define your box as a triclinic box with those tilt parameters set to zero instead of an orthogonal box. this is exactly what the example does that you are referring to! it uses an Si crystal with a diamond lattice with is a cubic structure as well. the example uses the “prism” region to define the box which implies that it is triclinic, but can just create an initial orthogonal box and then change it to (untilted) triclinic afterward with the change_box command.
axel.