Features

VQkit organizes its functionality into pre-processing, post-processing, and application-oriented analysis modules for VASP and Quantum ESPRESSO.

Pre-processing

Structure and input preparation

  • Create new VASP and Quantum ESPRESSO calculations.

  • Convert CIF structures into VASP or Quantum ESPRESSO input formats.

  • Convert completed calculation structures into reusable input files.

  • Freeze or fix selected atoms.

  • Delete selected atoms from a structure.

  • Perform pre-flight checks before calculations are submitted.

  • Prepare calculation directories and reusable input sets.

Pseudopotentials

  • Configure VASP pseudopotential libraries.

  • Generate VASP POTCAR files from configured libraries.

  • Configure Quantum ESPRESSO pseudopotential directories.

  • Assist with pseudopotential selection for supported workflows.

Brillouin-zone sampling

  • Generate regular K-point meshes.

  • Prepare symmetry-guided high-symmetry paths for band-structure calculations.

  • Support workflow preparation for both VASP and Quantum ESPRESSO.

Convergence workflows

  • Prepare plane-wave cutoff convergence calculations.

  • Prepare K-point convergence calculations.

  • Organize convergence-series directories and input files.

Reaction pathways and dynamics

  • Prepare nudged elastic band (NEB) calculations.

  • Generate NEB intermediate images.

  • Prepare ab initio molecular dynamics (AIMD) calculations.

  • Prepare selected structural and mechanical-property workflows.

Post-processing

The main post-processing interface is organized into the following analysis groups:

[1] General calculation analysis
[2] Structural analysis
[3] Electronic structure
[4] Charge, spin and bonding
[5] Energetics and thermodynamics
[6] AIMD / trajectory analysis
[7] Application-oriented analysis

General calculation analysis

  • Read completed VASP and Quantum ESPRESSO outputs.

  • Extract key calculation information.

  • Summarize selected convergence and run information.

  • Detect available outputs for downstream analysis.

Structural analysis

  • Analyze relaxed and final structures.

  • Inspect lattice parameters and cell properties.

  • Compare structures across calculation stages where supported.

  • Process reusable structural information from completed calculations.

Electronic structure

  • Density of states (DOS).

  • Projected density of states (PDOS).

  • Spin-resolved DOS and band analysis where available.

  • Band-structure analysis.

  • Band-gap determination.

  • Valence-band maximum (VBM) and conduction-band minimum (CBM) reporting.

  • Fermi-level analysis.

  • Work-function analysis.

  • Symmetry-guided band-path support.

  • Selected band-derived quantities where implemented.

Charge, localization, and bonding

  • Charge-density difference (CDD) analysis.

  • Electron localization function (ELF) analysis.

  • Bader charge analysis.

  • Direct use of existing Quantum ESPRESSO .cube files.

  • XY, XZ, YZ, and custom planar slices for volumetric data.

  • Atom overlays and numerical data export for supported plots.

  • Selected bonding and orbital descriptors where implemented.

Energetics and thermodynamics

  • Extract energies from completed calculations.

  • Support selected energy-difference and thermodynamic workflows.

  • Process energetics for application-oriented analyses.

AIMD and trajectory analysis

  • Temperature versus time.

  • Energy versus time.

  • Lattice and volume evolution.

  • Bond-distance evolution.

  • Mean-squared displacement (MSD).

  • Diffusion-coefficient estimation.

  • Radial distribution function (RDF).

  • Coordination-number analysis.

  • Trajectory-derived structural descriptors.

Mechanical and structural materials analysis

  • Prepare elastic calculations using energy-strain or stress-strain methods.

  • Analyze completed elastic calculations.

  • Obtain elastic stiffness and compliance information through the analysis workflow.

  • Calculate derived mechanical properties.

  • Evaluate elastic anisotropy and mechanical stability where supported.

  • Generate high-accuracy directional-elasticity surfaces.

  • Support VASP and Quantum ESPRESSO mechanical workflows.

Phonon-derived transport descriptors

  • Group velocity.

  • Gruneisen parameter.

  • Debye temperature.

Application-oriented analysis

VQkit includes specialized modules intended to connect general DFT outputs with common materials-research applications.

Supported or developing application areas include:

  • Battery materials.

  • Electrocatalysis.

  • Heterogeneous catalysis.

  • Mechanical and structural materials.

  • Phonon-derived transport analysis.

  • Supercapacitor-related analysis.

VASP and Quantum ESPRESSO support

VQkit aims to expose equivalent workflows through a common interface wherever practical. The exact files, keywords, and parsing logic remain code-specific.

Not every feature is necessarily available in identical form for both codes. The relevant documentation page should therefore be consulted for the requirements of each workflow.

Output and visualization

Depending on the selected workflow, VQkit can generate:

  • Processed numerical data files.

  • Publication-oriented plots.

  • Calculation summaries.

  • Reusable structural files.

  • Analysis-ready text outputs.

  • Intermediate files for subsequent calculations.

The original VASP and Quantum ESPRESSO files remain accessible so that results can be inspected, reproduced, and processed independently of VQkit.