[Wien] SCF convergence

[Luis Ogando]

Dear Wien2k community,

   We are trying do calculate the influence of zinc blend (ZB) stacking
faults on InP (sp semiconductor) wurtzite (WZ) systems using Wien2k 13. Our
first goal is to calculate the band gap change along the c-axis
(perpendicular to the interface between the two phases), similar to what
was done in J. Appl. Phys. 114, 033709 (2013) for two semi-infinite
structures.
   In our case, we use a supercell with three ZB cells along (111)
(hexagonal form) matched along "c" to a large sequence of WZ cells to
guarantee a minimum reproduction of a ZB environment in the stacking fault
region.
   We have done calculations for a system with 10 WZ cells, but the gap did
not change along the structure and we are now trying 15 WZ cells and the 3
ZB ones (78 atoms in total) to isolate neighbour stacking faults.
   As the gap is our main property, we are using the mBJ potential, but we
are facing convergence problems at the first (PBE) SCF calculation.
   We would be glad if someone could give us any hint about how to improve
the PBE scf convergence.
   Here we give some relevant parameters of our calculation (please, do not
hesitate in asking others):

*Species: "In" and "P"
*Number of atoms: 78
*RMT: 2.50 (In) and 2.10 (P)  (NN-DIST= 4.84768)
*RKmax: 9
*Emax: 5 (spin-orbit effects)
*XC: 13 (PBE)
*core-valence separation energy: -6.0
*GMAX: 20
*Inequivalent Kpoints: 12 increased to 24 after some iterations
*Mixing schema: MSR1 changed to PRATT with 0.15 mixing factor after some
iterations
*Calculation options: run_lapw -p -NI -ec 0.0001 -cc 0.0001 -i 150 -it
** We also attached the energy (Energy.dat) and charge (Charge.dat)
convergence evolution.


   Many thanks in advance.
   All the best,
                    Luis
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