# Precision of Plane-Wave Pseudopotential Method¶

At present, we limit the estimation of the numerical precision of plane-wave pseudopotential computations to the following list of parameters, as contained within the data structure for methods.

## Plane-wave¶

### Wavefunction Cutoff¶

The user can enter the kinetic energy cutoff of the plane-waves used to represent the electronic wavefunctions.

### Charge Density Cutoff¶

The user can also set the kinetic energy cutoff for the electronic charge density and potential.

## Reciprocal Space¶

### k-point Sampling¶

The k-points in the reciprocal space of the crystal structure need to be sampled, in order to reproduce the electronic structure of the symmetry-irreducible wedge of the Brillouin Zone.

### Electronic Occupations and Smearing¶

We review the importance of introducing an additional smearing factor, applied to the electron occupancies within crystal structures, in this page.

For a more in-depth explanation of the theory cited above, the reader is referred to the general review literature on the plane-wave pseudopotential formulation of Density Functional Theory listed in the corresponding references page.