Constrained DFT - Difficulty Finding Fermi Energy

Running Abinit Ground state
1

Dear all,

I am a new ABINIT user and am currently trying to compute the ground state of a set of materials as a function of the number of excited carriers, in order to investigate the possibility of a phase transition.

To do this, I have been varying the number of carriers. However, I always encounter the following error (I’ve tried for several nfqd values 0.2 - 1.5):

— !BUG
src_file: m_occ.F90
src_line: 759
mpi_rank: 0
message: |
It was not possible to find Fermi energy in 120 max bisections.
nelecthi: 2.50000000000002E-01, and nelectlo: 2.49999999999992E-01.
…
Could anyone help me understand what might be causing this error and how I should approach solving it?

Thank you in advance for your time and support.

Best regards,
Jorge

nboi2.abi (2.2 KB)
nboi2.abo (151.9 KB)

2

Dear Jorge,

To me it looks like you are dealing with a numerical inaccuracy.
My suggestion would be to check how does ecut and pawecutdg affect this behaviour.
Do you have the same behaviour if you increase pawecutdg to be larger than ecut? (as in 60 instead of 30?)

Let us know!
Bogdan