Correct, but scf convergence in CP is not THAT slow. The default value of the time step is dt=1, if I remember correctly. A value around 10 should yield a much faster convergence.
Paolo On Fri, Mar 12, 2021 at 10:18 AM Giuseppe Mattioli < giuseppe.matti...@ism.cnr.it> wrote: > > Dear Chris > scf convergence with cp.x actually used to be painfully slow! For this > reason, pw.x and cp.x should be interoperable, that is, you should be > able to restart a converged pw.x calculation with cp.x. Have a look > into the CPV/Restart_example/ directory, where restart details are > explained. > HTH > Giuseppe > > Quoting Christoph Wolf <wolf.christoph@qns.science>: > > > Dear all, > > > > I am trying to run an SCF calculation in cp.x (because I want to use the > > spin contamination analysis of cp.x), however reaching convergence with > > cp.x seems painfully slow - probably my fault as I am not familiar with > > cp.x. > > > > System is a spin polarized calculation for a molecule in a vacuum box. > The > > SCF calculation converges in 30 steps: > > > > ! total energy = -813.86536682 Ry > > Harris-Foulkes estimate = -813.86536682 Ry > > estimated scf accuracy < 1.3E-11 Ry > > > > But the cp.x calculation is still running after 2000 steps > > > > 1997 0.000605472420187 0.0 0.00 -406.607110121158 > > 1998 0.000604666115183 0.0 0.00 -406.607351342414 > > 1999 0.000603861731893 0.0 0.00 -406.607592243454 > > ... > > > > (NB: the energy difference between CP and PW at this point is > ~0.650182333 > > Ry) > > > > I am running the cp.x calculation with > > > > calculation = 'scf' > > and electron_dynamics = 'damp > > > > Is that the right way to do this? If yes, am I missing some critical > > parameters for improving convergence? > > > > I attached my input below - any help is much appreciated! > > > > Best, > > Chris > > > > &CONTROL > > calculation = "scf" > > prefix = "fepc" > > pseudo_dir = "/home/chwolf/Work/DFT/00_pseudo/" > > outdir = "tmp" > > wf_collect = .true > > tprnfor = .true. > > restart_mode = "from_scratch" > > nstep = 2000 > > / > > &SYSTEM > > ibrav = 0 > > nat = 57 > > ntyp = 4 > > nspin = 2 > > occupations = "fixed" > > ecutwfc = 60 > > ecutrho = 240 > > tot_magnetization=1 > > tot_charge=-1 > > starting_magnetization(1) = 0.5 > > starting_magnetization(2) = 0.0 > > starting_magnetization(3) = 0.0 > > starting_magnetization(4) = 0.0 > > nr1b=24, nr2b=24, nr3b=12 > > / > > &ELECTRONS > > conv_thr=1e-10 > > electron_maxstep = 350 > > electron_dynamics = 'damp' > > / > > > > CELL_PARAMETERS angstrom > > 29.47070000000000 0.00000000000000 0.00000000000000 > > 0.00000000000000 29.47070000000000 0.00000000000000 > > 0.00000000000000 0.00000000000000 15.000 > > > > ATOMIC_SPECIES > > Fe 55.9330 Fe_ONCV_PBE_sr.upf > > C 12.0107 C_ONCV_PBE_sr.upf > > N 14.0067 N_ONCV_PBE-1.0.upf > > H 1.0000 H_ONCV_PBE_sr.upf > > > > ATOMIC_POSITIONS angstrom > > ... > > .. > > > > -- > > IBS Center for Quantum Nanoscience > > Seoul, South Korea > > > > GIUSEPPE MATTIOLI > CNR - ISTITUTO DI STRUTTURA DELLA MATERIA > Via Salaria Km 29,300 - C.P. 10 > I-00015 - Monterotondo Scalo (RM) > Mob (*preferred*) +39 373 7305625 > Tel + 39 06 90672342 - Fax +39 06 90672316 > E-mail: <giuseppe.matti...@ism.cnr.it> > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > 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 206, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
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