To obtain PAW atomic data for ABINIT we use the AtomPAW atomic data generator.
From ABINIT version 5.8, it is included in the package as a plugin.

If you want to use AtomPAW with an older version of ABINIT (<5.8), you can follow the instructions given in the old AtomPAW-2-ABINIT manual pages.

1. How to get AtomPAW executable:

You can use one of these two possibilities:

• Use AtomPAW executable included in ABINIT package.
  Provided that ABINIT has been compiled with the --with-dft-flavor="...+atompaw..." option, the AtomPAW code is directly available from command line.
  First, just try to type: atompaw
  if "atompaw vx.y.z" message appears, everything is fine.
  Otherwise, you can try ~abinit_compilation_directory/plugins/atompaw/atompaw
  
  In order to compile AtomPAW plugin during ABINIT compilation, you need an Internet access.
  See ABINIT build system manual for additional information.

OR


• Use AtomPAW standalone version:
  Download AtomPAW from its web site
  Install it in a place of your choice (see installation instructions in user's guide).

2. How to use AtomPAW:

 1- Take a look at the user's guide for AtomPAW.
 2- Follow ABINIT tutorial named PAW2

AtomPAW execution follows the steps described below:

• Create a work directory ; use it for all that follows.


• Edit the input file for AtomPAW.
  You can find an example here (Oxygen).
  Input file syntax is explained in the user's guide
  Don't forget to add the 2 lines asking AtomPAW to produce the PAW dataset in ABINIT format:
  2
  default
  


• Run AtomPAW:        atompaw <X.input
  AtomPAW generates several files; only one is used by Abinit;
  others are useful to check the accuracy and transferability of the atomic data.

3. How to check the validity of PAW atomic data:

Everything is explained the user's guide.

The following remarks are quoted from the AtomPAW original paper by N. Holzwarth.

Iteratively check the following quantities before accepting a given set of projectors and basis functions:
  1- The PAW logarithmic derivatives for each atom should agree with the all-electron values within the energy range of interest.   See files logderiv.i
  2- The core electron density ncore should be sufficiently small for r>rc.   See file density
  3- The plane-wave cut-offs needed to converge the calculation (which can be determined with the help of the Fourier-space functions Fnili(q)), should be consistent with the computer resources available for the solid state calculations.    See files tprod.i
  4- For the material of interest, several solid state calculations should give reasonable results.

4. References:

5. Examples of AtomPAW atomic data for ABINIT:

	Input file for AtomPAW	"Psp" file for ABINIT
Silicon (Si)	Si.input	Si.abinit.paw
Oxygen (O)	O.input	O.abinit.paw

6. Contacts:

In case of problem or questions contact the authors:

Marc Torrent
Francois Jollet
Département de Physique Théorique et Appliquée
CEA, DAM, DIF
F-91127 Arpajon France