pymatgen.io.vasp.sets

Pymatgen's `pymatgen.io.vaspio_set` module provides functionality to handle VASP input and output sets[^1], which are sets of default computational settings used in the Vienna Ab initio Simulation Package (VASP) software. These include file format-specific settings such as POSCAR files for structural data and INCAR files for calculation parameters.

`vast_sets` can simplify managing complex simulations by abstracting the tedious task of writing raw VASP input files. For example:

1. Using a predefined set:

from pymatgen.io.vasp.inputs import Poscar
from pymatgen.io.vasp.sets import MaterialsProjectSet

set_obj = MaterialsProjectSet()
poscar_input = set_obj.get_poscar('mp-390')
poscar_input.write_file('POSCAR')  # Writes VASP-compatible POSCAR file

2. Customizing inputs from an existing set:

my_set = MaterialsProjectSet(relaxed=True)
my_set['INCAR']['ICHARG'] = 14  # Change ICHARG flag for relaxation calculations
my_set.write_input("custom_calculation")  # Produces an optimized run

Keep in mind that this functionality requires you to be familiar with the underlying VASP commands and terminology, since it doesn't generate all calculations directly – you're using sets as a template or guide.