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== {{TAG|INCAR}} == | == {{TAG|INCAR}} == | ||
The {{TAG|INCAR}} file holds the input parameters which "steer" the calculation. | |||
*The default values set by VASP itself are a clever choice to do standard calculations. | *The default values set by VASP itself are a clever choice to do standard calculations. | ||
*These standard settings can be modified to specify: | *These standard settings can be modified to specify: |
Revision as of 17:56, 24 June 2019
VASP basically needs 4 input files for standard production runs:
INCAR
The INCAR file holds the input parameters which "steer" the calculation.
- The default values set by VASP itself are a clever choice to do standard calculations.
- These standard settings can be modified to specify:
- What do you want to do? (scf calculation, DOS, dielectric properties ...)
- You can give parameters to fulfill your requirements concerning required precision, requested convergence, calculation time ...
POSCAR
- A simple POSCAR file may look like this:
fcc: Ni 3.53 0.5 0.5 0.0 0.0 0.5 0.5 0.5 0.0 0.5 Ni 1 Selective Dyn Cartesian 0 0 0 T T T
- The description of each line is given as follows:
- 1: Header (comment).
- 2: Overall scaling constant.
- 3-6: Bravais matrix.
- 4: Name(s) of the atom(s).
- 5: Number of the atoms (of each atom type).
- 6: (optional: selective dynamics).
- 7: Specifies which coordinate system is used ("cartesian" or "direct").
- 8-x: Positions of the atoms.
KPOINTS
The KPOINTS file determines the sampling of the 1st Brillouin zone.
- A typical KPOINTS file:
Automatic mesh 0 G (M) 4 4 4 0. 0. 0.
- The description of each line is given as follows:
- 1: Header (comment).
- 2: Specifies the k mesh generation type. : automatic generation scheme.
- 3: -centered (Monkhorst-Pack) grid.
- 4: Number of subdivisions in each direction.
- 5: Optional shift of the mesh.
POTCAR
- The POTCAR file contains the relevant information concerning the pseudo potentials that are necessary to run the calculation:
- Data that was required for generating the pseudo potentials.
- Number of valence electrons.
- Atomic mass.
- Energy cut-off.
- If the cell contains different atoms, the atomic POTCAR files have to be concatenated, in the same order as the atoms are given in the POSCAR file.
- Different XC-types must not be mixed.
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