I am in puzzle about the pdos when adopting different lorbit (<10 and >10) and the same RWIGS

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xinhuanwen · #1 Post by **xinhuanwen** » Wed Jul 18, 2012 3:01 pm

Dear everyone:

I am in trouble recently. I want to calculate the pdos at a specific atom, meanwhile the paw pseudo potential was chosen. For two differnet settings as follow, I got the different results.
(1) LORBIT=10
(2) RWIGS was set up in INCAR file and was same as that in POTCAR in units of A.
the different setting should have the same rwigs, but why does i get the different pdos.

thanks in advance.

jlbettis · #2 Post by **jlbettis** » Wed Jul 18, 2012 7:05 pm

xinhuanwen,
Your calculations are correct. You should get two different answers when setting the LORBIT-tag <10 and >10. As the manual states "The wavefunction character is calculated, either by projecting the orbitals onto spherical harmonics that are non-zero within spheres of a radius RWIGS around each ion (LORBIT=1, 2), or using a quick projection scheme relying that works only for the PAW method (LORBIT=10,11,12, see below)" Therefore, by setting LORBIT-tag <10 or >10 will cause VASP to use different "schemes" to calculate the PDOS... This is what I think... I am not sure.

xinhuanwen · #3 Post by **xinhuanwen** » Thu Jul 19, 2012 2:22 pm

Dear jlbettis:
Thank you for your reply. I think you are right. But do you know what methods in details the two different setting use? From the outcomes, i can find that for the Si monocrystalline, the pdos onto a d orbital of a Si atom is zero corresponding to lorbit =10. But the other setting(lorbit <10) makes the pdos onto the same d orbital be not zero.