Anaddb interpolation erro

Running Abinit Other tools and postprocessing in ABINIT
1

Hi,

I’m working on a cubic cell of 56atoms, space group 212. I calculated the electric field perturbation in 2x2x2 kpoint mesh. Then I merged all the derivated databases (DDB) files with mrgddb code. Then I performed the anaddb calculation to obtain Phonon bandstructure and phonon density of states for a qpoint mesh of 2x2x2. Here I’m facing the problem.

Based on the tutorial and theory, I’m supposed to obtain the phonon bands and phonon density of states in a finer mesh better than qpoint 2x2x2. When I try double grid as - 4x4x4 it says my DDB database is missing some points on those 4x4x4 mesh. Although, I’m providing the phonon wavevector list (qph1l) based on 2x2x2 mesh. I tried qph1l with 4x4x4 mesh qpoints, it shows the same error saying my DDB file is missing some qpoints. If I had to obtain the DDB files for a 4x4x4 mesh then there’s no point of that interpolation. I think I’m making a mistake somewhere. Could anyone please guide me with a solution how can I obtain Phonon Bandstructure and Phonon Density of States with a finer mesh?

I’m adding the input files for anaddb files that I’ve used -
phonon4.abi (2.2 KB)
phonon5.abi (2.0 KB)
phonon7.abi (2.0 KB)

2

Hi sms,

Indeed when you run anaddb, the information from ngqpt has to match essentially what you have in the corresponding DDB file. At this stage of preprocessing anaddb will check if you have all the corresponding perturbations according to your structure/symmetry/number of q-points.

For the band structure, you need to provide the information about the band path and number of division on the shortest segment as you do for the electronic band structure. the logic is the same.
(see for example in the DFPT tutorial 2 - Part 5 DFPT2 - abinit ). I see you already did in your inputs, I am not sure what went wrong without looking at the log fle.

As an alternative, you can also pass the ddb file to abiview.py (part of abipy utility) and it will generate automatically both the bands and DoS of phonons.

As an another alternative, to avoid installing abipy, you can pass directly the ddb to the GUI on the abinit page: https://gui.abinit.org/

In any case, I leave here an example for an input for anaddb:

! here provide your input DDB
ddb_filepath = "your_ddb_file"

! output files
output_file = "your_processing_output"
outdata_prefix = "prefix_for_all_generated_output_files"

eivec   4
enunit  0
ndivsm 20
nqpath 5
qpath
0.0 0.0 0.0
0.5 0.5 0.0
0.5 0.5 0.5
0.0 0.0 0.0
0.5 0.0 0.0

ifcflag 1
ngqpt  2 2 2
q1shft 0 0 0
nqshft 1
asr 2 
chneut 1     
dipdip 1

nph2l 1
qph2l
0.0 0.0 1.0
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