Besides checking the cutoffs, you could try to lower the convergence treshold for the first scf calculation to make sure that forces and stresses are not totally crazy (actually, you should be sure they are converged with cutoffs too). Also, it could make sense to lower the initial trust radius. If you get not so accurate forces and stresses and the amplitude for the first move of ions and cell is too big your system could end up in a crazy configuration (it moves by much in the wrong direction) for which the scf cycle on charge density is not easy to converge.
Best, Matteo On Feb 21, 2018, at 5:05 PM, Thomas Brumme <[email protected]<mailto:[email protected]>> wrote: Dear Bibhas Manna, without any inputfile we can only guess what might be wrong. The cutoffs seem to be a good - at least for the start; you should always check that those are enough for your specific calculation. My guess would be: you should consider using smearing for the occupations, but without input... Why are you using the old 5.1 version? Kind regards Thomas On 21.02.2018 15:52, Bibhas Manna wrote: Dear QE users, I am using PWSCF v.5.1 for vc-relaxing a graphene sheet with platinum atom adsorbed on it. The very first SCF cycle successfully converges after 18 iterations but the problem arises with the immediate next SCF cycle which is not converging even after 100 iterations. I am using ecutwfc of 45 Ry and ecutrho of 400 Ry for pseudo potentials types : H.pbe-van_ak.UPF C.pbe-van_ak.UPF Pt.pbe-n-kjpaw_psl.0.1.UPF Could anyone please suggest me what may be the wrong with my code.. Any help in this regard is highly appreciable. Thanks and regards. Bibhas Manna Research Scholar IIT Kharagpur, India. _______________________________________________ Pw_forum mailing list [email protected]<mailto:[email protected]> http://pwscf.org/mailman/listinfo/pw_forum -- Dr. rer. nat. Thomas Brumme Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry Leipzig University Phillipp-Rosenthal-Strasse 31 04103 Leipzig Tel: +49 (0)341 97 36456 email: [email protected]<mailto:[email protected]> _______________________________________________ Pw_forum mailing list [email protected]<mailto:[email protected]> http://pwscf.org/mailman/listinfo/pw_forum ************************************************ Matteo Cococcioni Theory and Simulation of Materials École Polytechnique Fédérale de Lausanne
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