Okay I have managed to get the SCF loop to behave by changing diemix to 0.1 from 0.7, and it now converges in about 60 steps in the first Broyden iteration (output file is attached).
However, I have now encountered a new issue during subsequent SCF convergence loops during the Broyden structural relaxation iterations. The SCF initially improves finding convergence in ~30 steps for the first 5 Broyden iterations but then begins to deteriorate during steps 6 and 7, not finding convergence in 100 SCF steps, with the calculation crashing after the 7th Broyden iteration.
I should note that during some identical calculations (64 atoms Cd0.5Mn0.5Te) the SCF convergence does not deteriorate and the calculation completes successfully. Other times it crashes as described above.
When the SCF loop deteriorates, is this a case of the structural relaxation not finding it’s minimum? If so, how come the calculation crashes after the SCF loop has already completed and, according to the log file (last lines of log file attached), as Abinit is trying to create an HDf-5 file? The last line in the log file before the calculation terminates is always:
- Creating HDf5 file with MPI-IO support: tmp/den_o_GSR.nc
I’ve attached a figure showing the total energy as a function of stress on the supercell: this shows the structural relaxation progressing well before the stress suddenly increases and the calculation crashes.
If you have more understanding as to why this is happening - whether it is an issue with the code or a minimization problem - and what can be done to avoid it, please let me know!
den_oc2im2_d8_O2sm.out (263 KB)
den.log (7.74 KB)