CASTEP is a full-featured materials modelling code based on a first-principles quantum mechanical description of electrons and nuclei. It uses the robust methods of a plane-wave basis set and pseudopotentials.

CASTEP allows the calculation of many properties, with a variety of tools as the users disposal.


  • DFT XC-functionals
  • Hybrid functionals
    • Hartree-Fock with PBE (PBE0) (reference)
    • Becke exchange with LYP correlation (B3LYP) (reference)
    • Screened exchange (sX-LDA) : (reference)
    • The HSE family of functionals (including user-defined parameterisation) : (reference)
  • LDA+U
  • Semi-empirical dispersion corrections:
    • DFT+D (DFT+D, DFT+MBD) - TS, MBD, Grimme (D2, D3, D4), XDM
    • nterface to LibXC library of functionals (reference)

Structural Methods

  • Full variable-cell geometry optimisation using BFGS, LBFGS and TPSD
  • Geometry optimisation using internal co-ordinates
  • Geometry optimisation using damped molecular dynamics
  • Transition-state search using LST/QST method or NEB

Moleclar Dynamics

  • Molecular Dynamics including fixed and variable-cell MD
  • NVE, NVT, NPH and NPT ensembles
  • Path-integral MD for quantum nuclear motion

Vibrational Spectroscopy

  • Phonon dispersion and DOS over full Brillouin-Zone using DFPT methods
  • Phonon dispersion and DOS over full Brillouin-Zone using supercell methods
  • IR and raman intensities

Magnetic Resonance spectroscopy

  • Chemical Shifts
  • Electric Field Gradient tensors
  • J-coupling
  • Hyperfine and g-tensors

Optical and other Spectroscpies

  • EELS/ELNES and XANES Spectra
  • Optical matrix elements and spectra

Electronic Properties

  • Band-structure calculations
  • Mulliken population analysis
  • Hirshfeld population analysis
  • Electron Localisation Functions (ELF)


  • Supports Vanderbilt ultrasoft and norm-conserving pseudopotentials
  • Built in "On The Fly" pseudopotential generator
  • (non self-consistent) PAW for properties calculations

Electronic Solvers

  • Block Davidson solver with density mixing
  • Ensemble DFT for metals

Code and Parallelism

  • Runs on machines from a PC to a supercomputer
  • Modern code written in modular fashion in Fortran 2003
  • Parallel execcution using MPI and OpenMP
  • Data distribution over plane-waves, k-points, bands and property farms