For the list of all the possible phonopy tags, see [official documentation][d].
### Running the Jobs
### Running Jobs
Each unique displacement is named `POSCAR-XXX`, in our case we have only one, which is named `POSCAR-001`. If you are calculating plus and minus displacements, the minus displacement immediately follows the plus displacement.
Each unique displacement should then be moved to a separate folder, with every displacement file renamed to POSCAR, and POTCAR, [KPOINTS][3] and [INCAR][4] should be added.
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@@ -68,7 +68,7 @@ If one doesn't use the automatic settings for the KPOINTS generation, it is impo
During the calculation, we need to move one of the atoms specified in POSCAR and calculate the forces (`ISIF = 0`, `ISMEAR` according to the type of the material at question).
After this, we can submit the VASP calculation using the `qsub` command.
### Calculating the Force Constants
### Calculating Force Constants
After the calculations finish, we can generate the FORCE_SETS file using the following command:
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phonopy -f POSCAR-???.dir/vasprun.xml
```
### Calculating the DOS and Thermal Properties
### Calculating DOS and Thermal Properties
Assuming we wrote all of our required parameters (such as the q-point mesh) to the mesh.conf file, we can then derive the phonon density of states (DOS)
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which outputs the thermal properties in the thermal_properties.yaml file.
## Example of Calculating the Thermal Expansion Coeffiecients of Aluminum Using the VASP Code
## Example of the Calculation of Thermal Expansion Coeffiecients of Aluminum Using the VASP Code
To calculate the thermal expansion coefficients, we need to obtain the volume dependence, which means we need to repeat the previous example for several different volumes of our POSCAR. All the rules mentioned in the previous example (i. e. the initial POSCARs have to be relaxed) still apply. We are also going to need a file containing the energy-volume dependence. Assuming we have calculated, we can either parse the data ourselves, or use the vasprun.xml files from the static calculations and running a command
