Dear Reinaldo, Thanks, this sounds very promising! Did you have to use a tighter FFT grid or did the default work fine? Best, Michal Krompiec Merck KGaA
On Thu, 21 May 2020 at 13:20, Reinaldo Pis Diez <reinaldo.pisd...@gmail.com> wrote: > > Dear Michal and folks, > > A few days ago I've faced exactly the same problem after recompiling > QE 6.5 with LibXC 4.3.4 to use TB09 to see its effect on the band > gap of some semiconductors. > > What I saw instead is that an scf run of the SCAN functional, also a > metaGGA one, converges smoothly on top of a scf, relax or vc-relax > job using PBE, for example. TB09 and the others metaGGA available > show the divergent behavior you are mentioning. > > Then, I tried a TB09 job on top of the converged SCAN calculation > using restart_mode = 'restart' and the job converged in a few > iterations, no divergence was observed. After the TB09 scf job > converged, I was able to run nscf and bands jobs to obtain both DOS > and band structures. > > I understand this is not a solution, but a workaround as a more > elegant solution is found. > > Regards, > > Reinaldo Pis Diez > Center of Inorganic Chemistry > National University of La Plata > Argentina > > > Dear Paolo, > > I changed io_rho_xml.f90 so that if the kinetic energy density file > > isn't found, the array is set to 0: > > > > 155d144 > > < LOGICAL :: ekin_density_exists > > 172,180c161,164 > > < INQUIRE( FILE=TRIM(dirname) // "ekin-density", > > EXIST=ekin_density_exists) > > < IF ( ekin_density_exists ) THEN > > < CALL read_rhog( TRIM(dirname) // "ekin-density", & > > < root_bgrp, intra_bgrp_comm, & > > < ig_l2g, nspin_, rho%kin_g, gamma_only ) > > < WRITE(stdout,'(5x,"Reading meta-gga kinetic term")') > > < ELSE > > < rho%kin_g = 1.0 > > < ENDIF > > > > Now I can start a TB09 calculation from a PBE density, but still my > > test case diverges immediately (=faster than when starting from > > scratch), regardless of diagonalization method. For example: > > The initial density is read from file : > > ./sic.save/charge-density > > > > Starting wfcs from file > > > > total cpu time spent up to now is 0.3 secs > > > > Self-consistent Calculation > > > > iteration # 1 ecut= 82.00 Ry beta= 0.40 > > CG style diagonalization > > > > > > > > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > > Error in routine c_bands (1): > > too many bands are not converged > > > > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > > > > I would be very grateful for any suggestions. > > Best, > > Michal > > > > P.S. This is my input file: > > &CONTROL > > calculation = "scf" > > prefix = "sic" > > / > > > > &SYSTEM > > a = 4.34800e+00 > > ibrav = 1 > > ecutwfc = 82 > > ecutrho = 328 > > nat = 8 > > ntyp = 2 > > occupations = "fixed" > > input_dft='tb09' > > / > > &ELECTRONS > > electron_maxstep = 1000 > > conv_thr = 1e-10 > > mixing_mode = 'plain' > > mixing_beta = 0.4 > > startingpot = 'file' > > startingwfc = 'file' > > diagonalization = 'cg' > > / > > > > K_POINTS automatic > > 8 8 8 1 1 1 > > > > ATOMIC_SPECIES > > Si 28.08500 Si.upf > > C 12.01060 C.upf > > > > > > ATOMIC_POSITIONS {angstrom} > > Si 0.000000 0.000000 0.000000 > > Si 0.000000 2.174000 2.174000 > > Si 2.174000 0.000000 2.174000 > > Si 2.174000 2.174000 0.000000 > > C 1.087000 1.087000 1.087000 > > C 1.087000 3.261000 3.261000 > > C 3.261000 1.087000 3.261000 > > C 3.261000 3.261000 1.087000 > > > > On Fri, 8 May 2020 at 09:39, Paolo Giannozzi <p.gianno...@gmail.com> wrote: > >> On Thu, May 7, 2020 at 10:33 PM Michal Krompiec > >> <michal.kromp...@gmail.com> wrote: > >> > >>> it was suggested to start from a density calculated with a different > >>> functional, but when I try to read in PBE density, it complains that it > >>> cannot read the kinetic energy file (which obviously cannot be there). > >> > >> this can be easily changed, I think: just disable the check and set the > >> kinetic energy density to zero > >> > >>> Should TPSS or SCAN pseudos work better (and where do I get them from)? > >> > >> I don't think the problem is in the pseudos but in the nasty numerical > >> behavior of meta-GGAs. See for instance here: > >> https://gitlab.com/QEF/q-e/-/issues/32. Note that several bugs have been > >> fixed in the development version. > >> > >> Paolo > >> > >>> Thanks, > >>> Michal Krompiec > >>> Merck KGaA > >>> > >>> _______________________________________________ > >>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > >>> users mailing list users@lists.quantum-espresso.org > >>> https://lists.quantum-espresso.org/mailman/listinfo/users > >> > >> > >> -- > >> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, > >> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy > >> Phone +39-0432-558216, fax +39-0432-558222 > >> > >> _______________________________________________ > >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > >> users mailing list users@lists.quantum-espresso.org > >> https://lists.quantum-espresso.org/mailman/listinfo/users > > _______________________________________________ > > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > > users mailing list users@lists.quantum-espresso.org > > https://lists.quantum-espresso.org/mailman/listinfo/users > > . > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users