Dear memebers of this community: Although I am newbie in using ABINIT I though I understood the basic features of it until I confront myself to the example of positron calculations (/abinitx.x.x/tests/v4/Input/t95.in and /abinitx.x.x/tests/v4/Input/t96.in ). I found that for running that test (checking the outputs /abinitx.x.x/tests/v4/Refs/t95.out and /abinitx.x.x/tests/v4/Refs/t96.out ), the computation needed a pseudopotencial file for the atoms used (in these case Aluminium) and the one used this time was 13al.psppos file (for a view of it you can check this http://gnu.ethz.ch/debian/abinit/abinit-5.3.4/tests/Psps_for_tests/13al.psppos"). Reading futher I found that the pseudopotencial files used for positron calculations must be the FHI (Fritz-Haber-Institute) pseudopotentials and indeed the file from "ftp://ftp.abinit.org/pub/abinitio/Psps/LDA_FHI/13-Al.LDA.fhi"[/URL]) is very similar to 13al.psppos one. Similar but not equal! in fact, the files looks exactly the same but 13al.psppos has a block at the end that 13-Al.LDA-fhi does not!! (See, after line 1006 of 13al.psppos) Trying myself to make positron lifetime calculus for other elements I notice that I could not do it properly with the pseudopotencial files .fhi; meaning that this difference between 13-Al.LDA.fhi and 13al.psppos file is important to make this calculus right. The problem then resides on that: What is this final block of data in 13al.psppos pseudopotencial file that is the difference with 13-Al.LDA.fhi pseudopotencial file? How to "generate" similar blocks of data for other other elements so to "complete" their pseudopotencial files so to be able to use them in positron lifetime calculations in ABINIT? Please any member that has used ABINIT come here and try to explain me because I am confused!!!