Here we provide some examples of how to use the calculator, ranging from very
basic to more advanced. That all scripts here have been written in such a
fashion that they will run regardless of whether you have set
mode = 'run'
mode = 'queue' in your
.vasprc. Thus, if you are in queue mode on
the cluster a small job will be submitted.
Basics - relaxing a water molecule¶
This example illustrates how to relax a water molecule using VASP’s internal relaxation routines.
from ase.build import molecule from storq import Vasp # set up atomic configuration atoms = molecule('H2O') atoms.center(vacuum=4.0) # set up calculator calc = Vasp('water', atoms=atoms, xc='pbe', encut=300, ibrion=1, nsw=20, isif=2, ismear=0, sigma=0.05) # set submission options calc.configure(walltime='00:05:00', cores=4) # run vasp calc.get_potential_energy()
The first argument of the
Vasp constructor is the run directory where all VASP IO files will be created.
The configuration (ASE Atoms-object) is passed as a keyword argument.
(Note: The calculator is internally attached to the atomic configuration scuh that calling
atoms.get_potential_energy() still works.
The exchange-correlation functional is set via the special keyword argument
xc where only the name of the functional is needed.
INCAR parameters will be set automatically.
Options pertaining to job submission are set using the
configure() method of the calculator.
When submitting jobs via a queuing system, the results are not immediately available to the script.
The calculator handles this by simply returning
None if the calculation has not finished.
After the job is finished one can simply rerun the script.
This causes the calculator to restart and read the results without performing another calculation, after which additional analyses can be carried out.