# Components¶

We present in this page the different components (executables and flavors) comprised within the Quantum ESPRESSO distribution package.

Only those components implemented on our platform to date are mentioned here, as can be inspected from the lists of available executables and flavors under the Unit Editor Interface.

Implementation on our platform

The user who wishes for additional functionality to be added to our platform in future should express so via a support request.

## Executables¶

The core plane wave DFT functions of QE are provided by the PWscf (Plane-Wave Self-Consistent Field) component, further referred to under the name of its executable pw.x. Further components are included in the distribution package, such as the ph.x executable for performing phonon calculations via the density functional perturbation theory and linear response theoretical formalisms 6.

Complete documentation about the software package can be found in its corresponding website. The input file description for pw.x can be found in Ref. 1. The package-specific documentation 2 contains links to input descriptions for other executables as well.

The following executables have been implemented on our platform so far.

• pw.x: general-purpose executable (see its different computation flavors in the next section below).
• ph.x: calculates phonon frequencies and displacement patterns, dielectric tensors, effective charges (uses data produced by pw.x).
• projwfc.x: projects wavefunctions onto orthogonalized atomic wavefunctions.
• q2r.x: reads dynamical matrices produced by the phonon code ph.x for a grid of q-points, and calculates the corresponding set of interatomic force constants.
• dynmat.x: reads a dynamical matrix produced by the phonon code ph.x, diagonalises it, and writes the results to files, both for inspection and for plotting.
• matdyn.x: calculates phonons at generic q-points using the interatomic force constants computed by q2r.x.
• pp.x: data analysis and plotting.
• dos.x: calculates the Density of States (DOS).
• bands.x: re-orders the bands in the band-structure of the material, and computes band-related properties.
• neb.x 3 4: performs calculations of the energy profile of chemical reactions via the Nudged Elastic Band method.

## Flavors¶

The pw.x executable for the Quantum ESPRESSO modeling application, for example, allows for the execution of the following different types of calculation flavors 5.