Optimization

Optimization is the most common task in the daily calculation work, and we now can quickly generate the inputs for optimization task with the help of GVasp, the only need file is the *.xsd.

When prepared the *.xsd (from Material Studio Software) in workdir, run the command:

gvasp submit opt

and the inputs (INCAR, KPOINTS, POSCAR and POTCAR) will be generated.

Warning

The workdir should only have one *.xsd file, otherwise, the structure generated is unknown.

open low-first option

In the practical calculation, the structure optimization is time spent and one method to accelerate the optimization task can start from a low-accuracy calculation and then perform the normal calculation based the optimized low-accuracy structure.

Using GVasp, you can run the following command to perform such low-first calculation:

gvasp submit opt -l/--low

Note

In fact, in the latest version, we only set the ENCUT as 300 to perform the low-accuracy calculation.

The following arguments can be applied in all of the tasks.

specify potential

Certainly, if you don’t like the default potential (“PAW_PBE”), you can also transfer a argument by specify the potential you want, like this

gvasp submit opt -p/--potential PAW_PW91

Note

The potential can only specify to the member of the [‘PAW_LDA’, ‘PAW_PBE’, ‘PAW_PW91’, ‘USPP_LDA’, ‘USPP_PW91’]

Note

The -p/--potential accept one or more values, if you specify one potential, all the elements will use the same potential; and if you specify two or more potentials, the potential will auto corresponding to the element in POSCAR, noticed that the number of potential should equal to the number of elements in POSCAR

Important

The VASP provide the recommend potential for some elements (see here), and we also applied them in GVasp.

open the vdw-correction

The GVasp support including the van der Waals (vdw) correction in calculation, just by running the following command:

gvasp submit opt -V/--vdw

Note

Open the vdw option will set IVDW = 12 in INCAR file.

including the solvation effect

The GVasp support including the solvation effect in calculation, just by running the following command:

gvasp submit opt -S/--sol

Note

The default solvent is water, and you can modify it by adding EB_K argument in INCAR by yourself.

perform the Gamma-point calculation

Use single Gamma-point and vasp_gam to perform the calculation for the large-scale system can run the following command:

gvasp submit opt -G/--gamma

perform the HSE06 calculation

Use HSE06 method rather than the PBE method to perform the calculation can run the following command:

gvasp submit opt -H/--hse

perform the Static calculation

Perform the static calculation (NSW=1) can run the following command:

gvasp submit opt -SP/--static

perform charged system calculation

If you want to calculate a charged system by setting the NELECT argument, you can also use the GVasp to generate the inputs.

Take the +1 charged system as the example, the command line can be typed as this:

gvasp submit opt -N/--nelect +1

Note

The NELECT accept real number as its input, so the float input (e.g., -0.5) is also allowed.

Noted that the mentioned arguments can also be used lonely or together with other arguments, like this:

gvasp submit opt -G -V -S -P PAW_PBE -N/--nelect -0.5