Dear Lorenzo, Thank you. I am sure the system is not metallic, the band gap (calculated with PBE) should be around 0.59 eV (vs. experimental 1.41 eV). I tried your suggestions, but with no luck (energy oscillates instead of converging). I tried changing mixing_beta from 0.05 to 0.9, increasing and decreasing number of k-points - still the same. In the meantime, I did a calculation on exactly the same system in CASTEP without any problems (default settings, 3x3x3 Monkhorst-Pack grid), with on-the-fly USPs and also with norm-conserving ones. So clearly I am doing something wrong or there is something not right with my QE build (6.3, compiled with Intel 2017 compilers and Intel MPI). I would be very grateful for any further suggestions.
Best wishes, Michal On Tue, 9 Oct 2018 at 10:57, Lorenzo Paulatto <[email protected]> wrote: > On 09/10/2018 11:52, Michal Krompiec wrote: > > Hello, > > I'm struggling with SCF convergence of something that should be a simple > > calculation: InP (zincblende structure taken from a CIF). I tried > > ultra-soft pseudopotentials, PAW, changing the k-point grid, increasing > > ecutwfc and ecutrho, decreasing mixing_beta and every time the SCF > > energy is oscillating instead of converging. I would be grateful for any > > advice. > > Hello, are you sure you system does not turn out to be metallic? That > would make convergence problematic. > > Try this the following input (I have removed all input variables that > you MUST NOT use, unless you really know what you are doing). If it > works remember to check convergence with ecutwfc/wcutrho (your values > look very high to me) and of the k-points w.r.t. the degauss value. > > cheers > > &CONTROL > calculation = "scf", > pseudo_dir = ".", > outdir = ".", > prefix = "InP", > verbosity='high' > restart_mode = "from_scratch" > / > &SYSTEM > ibrav = 2, > nat = 2, > ntyp = 2, > ecutwfc = 80, > ecutrho = 800, > occupations = "smearing", > smearing="mv" > degauss=0.02 > A=5.8687, > > > / > &ELECTRONS > mixing_beta=0.2, > mixing_mode="plain" > / > > > ATOMIC_SPECIES > In 49 In.pbe-dn-kjpaw_psl.1.0.0.UPF > P 15 P.pbe-n-kjpaw_psl.1.0.0.UPF > > ATOMIC_POSITIONS {alat} > In 0.00000 0.00000 0.00000 > P 0.25 0.25 0.25 > > K_POINTS {automatic} > 9 9 9 0 0 0 > > > > Thanks in advance, > > > > Michal > > > > > > *Dr. Michal Krompiec* > > > > Adjunct Professor > > > > School of Chemistry, University of Southampton > > > > Highfield, Southampton SO17 1BJ, UK > > > > > > and > > > > Head of Computational Modelling | Performance Materials | Early Research > > and Business Development > > > > Merck > > > > > > > > _______________________________________________ > > users mailing list > > [email protected] > > https://lists.quantum-espresso.org/mailman/listinfo/users > > > > -- > Lorenzo Paulatto - Paris > _______________________________________________ > users mailing list > [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users
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