Text Size
Wednesday, June 19, 2013

NEW RELEASE: PAW datasets!

After long and careful consideration we have decided to release a new set of POTCAR files covering the periodic table. This includes GW potentials for almost all elements.

You will find the new potentials on the download-portal and on the VASP.5.X user account of the ftp server.

The potentials have been tested using standard DFT-"benchmark" runs
(see the data_base file in the tar files).
In most cases the potentials are literally identical to the
previous releases, but ALL have been recalculated using
a new version of the PAW generation code, to
include additional information allowing for calculations
with meta-GGA functionals. The present potentials can be
used in VASP.4.6, but we strongly recommend to use them only
in VASP.5.X, since some compatibility issues might emerge
(e.g. LDA+U).

Notable updates:
Many of the 4d and 5d potentials have been updated
to improve f-scattering properties. This decreases the lattice
constants slightly for metals, and it might make a substantial
difference for strongly ionic TM compounds (including oxides).

As you will realize, we now have a large number of potentials
for some elements. The rules which potential to use are
identical to previous releases (nothing new here).

Of course the GW potentials are all "new".
As you will see (database) they give virtually identical results
to the standard potentials, and it is safe to assume
that one can use the GW potentials instead of standard
LDA/GGA potential for groundstate calculations, without
deteriorating the results. In fact, we believe the
GW potentials are generally at least as good as the old standard
potentials, but might be much better for some "groundstate" properties
including EFG and NMR (well, matter of fact, these are
properties related to excitations).

However, the GW potentials yield much better scattering
properties at high energies well above the Fermi-level
(typically up to 10-20 Ry above the vacuum level).
We believe that this is important for GW and RPA calculations,
although firm proof is still missing.

For GW calculations, we also recommend to treat as
many electrons as computationally feasible as valence
electrons (e.g. use Zn_sv_GW for GW, whereas the Zn or Zn_GW
potentials are sufficiently accurate for groundstate calculations).

The LDA and PBE sets are identical, except for the lanthanides,
for which only PBE potentials are available.

Cheers,

The VASP team