ezvasp

Syntax: ezvasp [-c] [-s] [-n] [-p "..."] input_file

-c: Cell patch. This option will convert the cell you entered into a cell that has the symmetry 
                     needed for
    vasp to work properly. The atom positions are altered correspondingly.

-s: Static run. After the relaxations are completed, this option makes vasp start again, turning off 
                     relaxations
    and turning on tetrahedron integration with bloech correction. Can acheive the same effect by
    including DOSTATIC in the INCAR portion of the input file.

-n: do Not run vasp. If you want to create the input files now and run them later, perhaps on 
                     another machine.

-p: name of the vasp command ("vasp" by default). You can include addition prefix such as:
    ezvasp -p "rsh remote.machine nice +5 /usr/local/bin/vasp" vasp.in

Here is an example of input file:

[INCAR]
SYSTEM = FeNi
ISPIN = 2
PREC = HIGH
ISMEAR = 1
NSW=41
SIGMA = 0.1
IBRION = 2
ISIF = 3
ENMAX = 400
EDIFF = 1e-6
EDIFFG = 1e-4
KPPRA = 1000
USEPOT = PAWGGA
DOSTATIC
SUBATOM = s/Fe$/Fe_h/g
KSCHEME = GAMMA
MAGATOM =

[POSCAR]
 SOME TITLE
 3.55
  -.500000000     -.500000000    -1.000000000   
   .500000000    -1.000000000     -.500000000   
  -.500000000      .500000000     1.000000000   
 1 2
 Direct
  .33333     .33333     .00000     Fe+5
  .00000     .00000     .00000     Vac
  .66667     .66667     .00000     Fe-5

End of example.

Note that there 6 new tokens in the INCAR section.

1) KPPRA stands for "K-Point Per Reciprocal Atom". This is a way to automatically set the k-point 
                     mesh for
   a number of similar systems. Here is how it works. If you know that you need 500 k-points for a 
                     2-atom
   structure, then you type in 1000. If you now try a similar structure with 4 atoms, the code 
                     automatically
   use 250 k-points. The mesh along the three axes is automatically chosen to make the mesh as 
                     uniform as possible.
   (For the algorithm, see atat/src/kmesh.c++).
   You can also specify KPPRA = UPDIR which indicates that the KPOINTS file
   found one directory above should be used.
   (This is useful for cell distorsions used in elastic constant calculations of constituent strain 
                     runs).
   If this token is ommited, you need to specify a [KPOINT] section in the input file that contains 
                     what
   you want the KPOINT file to be.

2) DOSTATIC indicates that a static run must be done after the relaxation run (NSW tag is removed 
                     and the ISIF and IBRION
   token are ajusted accordingly). The output files named *.relax contain the result of the (first)
   relaxation run while the files named *.static contain the results of the (second) static run.
   When DOSTATIC is not specified, all output files are named *.static , whether the VASP input 
                     parameters
   allow relaxations or not.

3) KSCHEME specifies the type mesh to use: Gamma shift or Monkorst-Pack. The default is Gamma if 
                     KSCHEME is ommited. You can
   also specify (on a separate line) KZ1 to force one k-point along the 3rd axis, which is useful 
                     for slabs.

4) MAGATOM is similar to the usual token MAGMOM used to specify the moment on each atom. The novelty 
                     is that you specify the
   moments in the POSCAR section. (In version 3.15 and above, this token can be ommited. Having 
                     spins specified in the POSCAR
   section turns this on automatically. It also set ISPIN=2 automatically.)
   The usual MAGMOM token is still available (but you cannot use both MAGMOM and MAGATOM).

5) USEPOT 
   selects the potentials used: LDA GGA PAWLDA PAWGGA PAWPBE (or any other potential defined in 
                     .ezvasp.rc)
   By default, LDA (without PAW) is used.
   For backward compatibility, you can also use the tag DOGGA instead of USEPOT = GGA

6) The SUBATOM token lets you specify a sed-like substitution command to be
   applied to the name of the atomic species.
   For instance, SUBATOM= s/Fe$/Fe_h/g  will cause ezvasp to use the Fe_h
   pseudopotential instead of the Fe one. Multiple SUBATOM token can be given,
   one for each substitution. Don't forget the s/ and /g and the $ after the first element name
   (to avoid F matching Fe, or Y matching Yb).

There are also familiar VASP tokens that are robustified. For instance ISTART = 2 does not work 
                     unless you force
the FFT grid size to match the earlier run.
To help with this, ezvasp fetches the right NGX,NGY,NGZ from the previous run's OUTCAR or CHGCAR in 
                     the current directory.

There are new features in the POSCAR section as well.
1) The line that specify the number of atoms (here 1 2) can be ommited (it is ignored).
2) The atomic species are specified to the right of the atom positions.
   The corresponding POTCAR are automatically copied. You can specify pseudopotentials like Li_h or 
                     O_s.
3) The number following the species is the magnetic moment on the atom (if MAGMOM is in the INCAR 
                     section).
   Identical species with different moments will be considered symmetrically distinct to allow for
   symmetry-breaking relaxations.
4) Do not specify "selective dynamics". It will be written to the INCAR file
   automatically if you include T's and F's after the atom species, e.g.:
    0.5 0.5 0.5 Al T T F
5) The element "Vac" or "Va" stands for vacancy. It is ignored for everything but
   to compute the k-point mesh with the KPPRA option.