[Pw_forum] Converting pseudopotentials from CPMD
giannozz at democritos.it
Fri Nov 25 18:46:34 CET 2011
On Nov 25, 2011, at 17:02 , Merlin Meheut wrote:
> However, for the rest of the file, the CPMD file has only a &POTENTIAL
> field with 2S and 2P potentials, whereas the UPF file have <PP_RAB> ,
> <PP_LOCAL>, and <PP_NONLOCAL> fields, and I do not see any agreement
> between the two. What should be the connection?
the contents of the UPF file is documented (sort of) (but more than
file formats) here:
UPF always assumes a fully nonlocal form. Most other file formats
semilocal form. Transforming the latter into the former requires
orbitals and a choice for the local reference term (Kleinman-Bylander
Unless you use the Gauss-Hermite technique, you also need to choose a
local potential in CPMD (for light elements, l=1 is the typical
choice). Of course,
the choice of the local potential affects the results, sometimes in
> The cpmd file seems quite simple, with two wavefunctions, two
> and one nlcc field. Where is the difficulty of the conversion?
oh, nothing: trivial stuff. You just have to spend a few days chasing
before realizing that there is a missing 2 or r^2 or 1/r factor
And don't count on documentation: reverse engineering is the only thing
that (sometimes) works.
I have recently used and extended the cpmd2upf converter. All
are in the 4.3.2 version: more checks, more CPMD formats are recognized.
I am not aware of any major problem, but I haven't tried anything with
Paolo Giannozzi, Dept of Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
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