Skip to content

Total Energy

Scalar Electronic

The "Total Energy" refers to the total electronic ground state energy of a material with a fixed lattice (with no thermal vibrations of the atoms). It is an important example of an Auxiliary property of Materials, and is routinely calculated during the course of material science simulations.

Examples

The total energy can be calculated by a corresponding workflow. For DFT calculations, for example, any Workflow containing a unit with a "self-consistent field" (scf) type can extract total energy.

It is presented to the user, as part of the output of a Job, with the appearance displayed below, under the interface of the Results Tab of the Job Viewer. Its final value is expressed in units of electronVolt (eV).

Total energy

-8.922

Total Energy Contributions

The Total Energy of a Material is comprised of several Energy Contributions. They are returned as a list of Scalar and Auxiliary quantities.

Types of Contributions

Specific types of energy contributions are commonly encountered in DFT computations 1, 2. The types included in the final results depend specifically on the modeling application employed, as explained in what follows.

The reader is referred to the links presented at the bottom of the page for a theoretical review of the energy contributions presented herein.

By Application

Generic

The following contributions, displayed in the image below, are computed and returned to the user under the Results Tab of Job Viewer, for the cases of both VASP and Quantum ESPRESSO calculations. In all instances, the results are returned in units of eV.

Common Contributions

Quantum ESPRESSO

Two additional energy contributions can be evaluated with Quantum ESPRESSO-based Workflows: the "One-electron" and "Harris-Foulkes" contributions 3. They are both returned as values expressed in eV, in a similar format to the other properties listed in the above image.

Schema

The JSON schema and an example representation for the total energy can be found here, whereas that for its contributions here.