# Average Pressure¶

We define the Average Pressure $p_{avg}$ of a Material as a Scalar and Physical property obtained from the following conventional formula.

p_{avg}=-\frac{1}{3} \mathrm{Tr} \hspace{1pt} {\boldsymbol{\sigma}}

where ${\boldsymbol{\sigma}}$ is the internal stress tensor of the solid, and $\mathrm{Tr}$ indicates the Trace operator in linear algebra 1.

## Example¶

The average pressure can be computed as part of any Workflow involving at least one basic "self-consistent field" (scf) total energy calculation in DFT.

It is then presented to the user, as part of the output of a Job, with the following appearance under the interface of the Results Tab of Job Viewer. Its final value is expressed in units of kilobars (kbar).

Pressure

## Schema¶

The JSON schema and an example representation for this property can be found here.