How to build PAW atomic datasets for ABINIT using AtomPAW generator

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

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.
  Just try to type: ~abinit_compilation_directory/fallbacks/export/bin/atompaw-abinit if "atompaw vx.y.z" message appears, everything is fine.
  In order to compile AtomPAW plugin during ABINIT compilation, you may 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 (nickel).
  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 XML format (according to standard specification):
  XMLOUT
  default
  or in ABINIT proprietary format:
  ABINITOUT
  default
• Run AtomPAW: atompaw <X.input
  AtomPAW generates several files; the PAW atomic dataset for ABINIT can be found in the *.xml or *.pawps files.
  Other files 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 in the user's guide.
The following remarks are quoted from the AtomPAW original paper:

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 F_nili(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

[1]  A Projector Augmented Wave (PAW) code for electronic structure calculations, Part I: atompaw for generating atom-centered functions (local copy)
A. R. Tackett, N. A. W. Holzwarth, and G. E. Matthews, Computer Physics Communications 135, 329-347 (2001)

[2]  Orthogonal polynomial projectors for the projector augmented wave method of electronic structure calculations (local copy)
N. A. W. Holzwarth, G. E. Matthews, A. R. Tackett and R. B. Dunning, Phys. Rev. B 57, 11827-11830 (1998)

[3]  Comparison of the PAW, pseudopotential, and LAPW formalisms for density functional calculations of solids (local copy)
N. A. W. Holzwarth, G. E. Matthews, R. B. Dunning, A. R. Tackett and Y. Zeng, Phys. Rev. B 55, 2005-2017 (1997)

[4]  Real-space implementation of nonlocal pseudopotentials for 1st-principle total-energy calculations
R.D. King-Smith, M.C. Payne and J.S. Lin, Phys. Rev. B 44, 13063 (1991)

[5]  Implementation of the projector augmented-wave method in the ABINIT code: Application to the study of iron under pressure
M. Torrent, F. Jollet, F. Bottin, G. Zerah and X. Gonze, Computational Materials Science 42, 337 (2008)

[6]  Electronic structure packages: two implementations of the Projector Augmented-Wave (PAW) formalism (local copy)
M. Torrent, N. A. W. Holzwarth, F. Jollet, D. Harris, N. Lepley and X. Xu, Computer Physics Communications 181, 1862 (2010)

5. Contact

In case of problem or questions contact the authors:

Marc Torrent
Francois Jollet
Département de Physique Théorique et Appliquée
CEA-Bruyères-le-Châtel, France

Natalie Holzwarth
Department of Physics
Wake Forest University, Winston-Salem (NC), USA