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Average Pressure

Scalar Thermodynamic

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.


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).




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