# Convergence Tools: Brillouin Zone sampling#

Then click on the *Parameters* icon to open the Convergence tools: BZ sampling
parameters widget.

On the right side of the Parameter widget, you can see the Monkhorst-Pack grid that will be used for each of the single-point calculations. You can modify the BZ sampling by tuning the following parameters:

**Monkhorst-Pack grid**. Initial Monkhorst-Pack grid.ASAP also indicates the corresponding k-grid cutoff, a parameter determining the fineness of the k-grid used for Brillouin zone sampling. The k-grid cutoff is half the length of the smallest lattice vector of the supercell required to obtain the same sampling precision with a single k point.

**Scaling of Monkhorst-Pack grid**. The minimum (*initial*) and maximum (*final*) scaling applied to the MP grid previously indicated.**Number of grids**. To indicate the total number of grids to be created.**Type of grids**. To indicate if you desire to include only even or odd Monkhorst-Pack grids.

Press the **Update BZ samplings** button to update the list of grids displayed
in the right side of the Parameter widget.

**OK**button to close the IET widget once the parameters are properly set.

*Calculator*icon to select the computational engine to be used during geometry optimisation.

*Run*icon to open the Run widget. Then click on the

**Run**button to submit the set of calculations required to perform the BZ sampling.

*Calculator output*tab in the Run widget shows the complete calculation output in real time.

In addition, the *Task output* tab in the Run widget shows relevant
information of Geometry optimisation output in real-time.

## Convergence Tools. Brillouin Zone sampling workflow: Analysis#

When the calculation is completed, select **Exit and analyse** to open the
analysis widget.

Select one of the **Plot type** options to visualise the energy deviation,
maximal force deviation or Frobenius norm of stress deviation computed for
each of the used Brillouin zone (BZ) sampling grids. Each deviation is
computed using the corresponding value obtained with the highest BZ sampling
grid.