ABINIT Discussion Forums

Dear all,

when running non-linear calc, I get an error -

In a non-linear response calculation, nband must be equal
to the number of valence bands.

I'm trying to calc. the Raman spectrum of boron (50% doping) doped TiO2. Ti pseudo has 12 valence electrons (2 Ti atoms in the unit cell), O has 6 (3 atoms) and B has 5 (1 atom). I count that would make 47 valence electrons, which occupy 24 bands. This is what I get in the output, when I set all nbands to 24:


occ1 2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 1.000000
occ3 2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 1.000000
occ4 2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 1.000000
occ5 2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 2.000000
2.000000 2.000000 2.000000 2.000000 2.000000 1.000000


Setting nband to 23 or 25 also gave the same error. Could someone help me with this issue? I would appreciate any comment and lecture.

Thank you in advance!

Yours,
Igor Lukacevic

Hi Igor,

this system is open shell, so "metallic" and the nonlinear stuff can not deal with it...

ciao

Acknowledged, sir!

Igor

ilukacevic wrote:Acknowledged, sir!

Igor

Correction - the system is not metallic, I use default occopt. it's open shell only because the B pseudo has an odd number of valence electrons. If I took the one with even number of valence electrons, it wouldn't be open shell, right? And the code would work, right?

Igor

B will always have an odd number of electrons... And in some cases you get metals with even numbers of electrons, so it's not a guarantee. Need to see the electronic structure and make sure you have a proper gap... But the code only stops if it sees that there are unfilled bands (occ < 2.0)