recpot format? (CASTEP & ONETEP)

[mkrompiec]

Hi, would it be possible to generate files in .recpot format, native to CASTEP and ONETEP? OPIUM does recpot, but Rappe's group library has much smaller element coverage...

[gmatteo]

Hi,

At present, the pseudopotential generator can produce pseudos in the psp8, upf2 and psml format.

I see two possible solutions.

1. Add support for the recpot format to the oncpsp code
   so that one can use the pseudo-dojo input files to generate recpot files.

2. Interface CASTEP and ONETEP with the libPSML library
   to read pseudopotentials in the PSML format. In this case, one can immediately reuse
   the psml files available on our website

[mkrompiec]

Solution 1 would be ideal :)

[gmatteo]

In my experience, both solutions require the participation of an expert-user or a developer
of the ab-initio code you want to support.

If you opt for solution 1 you need someone who knows the specifications of the recpot format
and how to convert the internal representation in oncvsp to the final format taking the different
cases into account (scalar-relativistic, fully-relativistic with SOC, model core charge, XC functional).
Besides I would suggest to contact Don Hamann before starting to work on a new converter in oncvpsp.

Solution 2 is the one that, in my opinion, will pay more in the long-term because
developers can focus on a single format and users can employ different codes and different
basis sets without having to deal with different formats.