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VASP the GUIDE

written by Georg Kresse and Jürgen Furthmüller
Institut für Materialphysik,
Universität Wien,
Sensengasse 8, A-1130 Wien, Austria

Vienna, February 7, 2003

Introduction
Contents
New features added
- VASP.4.4 (for users upgrading from VASP.4.3)
- VASP 4.4.4 and VASP.4.4.5
- VASP 4.5
- VASP 4.6
VASP an introduction
- History of VASP
- Outline of the structure of the program
- Tutorial, first steps
  - diamond
The installation of VASP
- How to obtain the VASP package
- Installation of VASP
- Compiling and maintaining VASP
- Updating VASP
- Pre-compiler flags overview, parallel version and Gamma point only version
- Compiling VASP.4.X, f90 compilers
- Performance optimisation of VASP
- Performance profile of some machines, buyers guide
- Performance of serial code
- Performance of parallel code on T3D
Parallelization of VASP.4
- Fortan 90 and VASP
- Most important Structures and types in VASP.4.2
- Parallelization of VASP.4.x
- Files in parallel version and serial version
- Restrictions in VASP.4.X and restrictions due to parallelization
Files used by VASP
- INCAR file
- STOPCAR file
- stdout, and OSZICAR-file
- POTCAR file
- KPOINTS file
  - Entering all k-points explicitly
  - Strings of k-points for bandstructure calculations
  - Automatic k-mesh generation
  - hexagonal lattices
- IBZKPT file
- POSCAR file
- CONTCAR file
- EXHCAR file
- CHGCAR file
- CHG file
- WAVECAR file
- TMPCAR file
- EIGENVALUE file
- DOSCAR file
- PROCAR file
- PCDAT file
- XDATCAR file
- LOCPOT file
- ELFCAR file
- PROOUT file
  - Format:
The param.inc file
- makeparam utility
- NGX,Y,Z and NG(X,Y,Z)F parameters
- NBANDS parameter
- NTYPD, NIOND, NKDIM parameters
- NBLK, MCPU parameter
- NRPLWV, NPLINI parameter
- LDIM, LMDIM, LDIM2, LMYDIM parameter
- IRECIP, IRMAX, IRDMAX parameter
- IALLD parameter
- IRMMD parameter
- NEMPTY parameter
- ISPIND parameter
- IGRAD parameter
- Which parameters are really important
- Memory requirements
The INCAR File
- All parameters (or at least most)
- NGX, NGY, NGZ, NGXF, NGYF, NGZF, NBANDS, NEDOS, NBLK
- SYSTEM-tag
- NWRITE-tag
- ENCUT-tag
- ENAUG-tag
- PREC-tag
- ISPIN-tag
- MAGMOM-tag
- ISTART-tag
- ICHARG-tag
- INIWAV-tag
- NELM,NELMIN and NELMDL-tag
- EDIFF-tag
- EDIFFG-tag
- NSW-tag
- NBLOCK and KBLOCK-tag
- IBRION-tag, NFREE-tag
- POTIM-tag
- ISIF-tag
- PSTRESS-tag
- IWAVPR-tag
- ISYM-tag and SYMPREC-tag
- LCORR-tag
- TEBEG, TEEND-tag
- SMASS-tag
- NPACO and APACO-tag
- POMASS, ZVAL
- RWIGS
- LORBIT
- NELECT
- NUPDOWN
- EMIN, EMAX tag
- ISMEAR, SIGMA tag
- LREAL-tag (and ROPT-tag)
- GGA-tag
- VOSKOWN-tag
- DIPOL-tag (VASP.3.2 only)
- ALGO-tag
- IALGO, and LDIAG-tag
- NSIM - tag
- Mixing-tags
- WEIMIN, EBREAK, DEPER-tags
- TIME-tag
- LWAVE,LCHARG
- LVTOT-tag, and core level shifts
- LELF
- Parallelisation: NPAR switch, and LPLANE switch
- LASYNC
- LscaLAPACK, LscaLU
- Elastic band method
- PAW control tags
- Monopole, Dipole and Quadrupole corrections
- Dipole corrections for defects in solids
- Band decomposed chargedensity ( parameters)
- Berry phase calculations
  - LBERRY, IGPAR, NPPSTR, DIPOL tags
  - An example: The fluorine displacement dipole (Born effective charge) in NaF
- Non-collinear calculations and spin orbit coupling
  - LNONCOLLINEAR tag
  - LSORBIT tag
  - Symmetry restrictions
- Constraining the direction of magnetic moments
- On site Coulomb interaction: L(S)DA+U
- Frequenly used setting in the INCAR file
  - Static calculations
  - Continuation of a calculation
  - Efficient relaxation from an unreasonable starting guess
  - Efficient relaxation from a pre-converged starting guess
  - Molecular dynamics
  - Making the calculations faster
- Not enough memory, what to do
Theoretical Background
- Algorithms used in VASP to calculate the electronic groundstate
- Wrap-around errors -- convolutions
- Non-selfconsistent Harris-Foulkes functional
- Partial occupancies, different methods
- Forces
- Volume vs. energy, volume relaxations, Pulay Stress
The most important parameters, source of errors
- Number of bands NBANDS
- High quality quantitative versus qualitative calculations
- What kind of ``technical'' errors do exist, overview
- Energy cut-off ENCUT, and FFT-mesh
- When to set ENCUT (and ENAUG) by hand
- Number of k-points, and method for smearing
Examples
- Simple bulk calculations
- Bulk calculations with internal parameters
- Accurate DOS and Band-structure calculations
- Atoms
- Determining the groundstate energ of atoms
- Dimers
- Molecular -- Dynamics
- Simulated annealing
- Relaxation
- Surface calculations
- Lattice dynamics, via the force constant approach
Pseudopotentials supplied with the VASP package
- Two versions of PP, which one should be used
- The PAW potentials
The pseudopotential generation package
- V_RHFIN, V_RHFOUT V_TABIN AND V_TABOUT file
- PSCTR
- Default energy cutoff
- TAGS for the rhfsps program
- TAGS for the fourpot3 program
- PSOUT file
- FOUROUT file
- DDE file
General recommendations for the PSCTR files
Example PSCTR files
- Potassium pseudopotential
- Vanadium pseudopotential
- Palladium pseudopotential
- Carbon pseudopotential
- Hydrogen pseudopotential
Important hints for programmers
FAQ
Bibliography
About this document ...

Georg Kresse
2003-02-07