The input data use PBE + DFT-D3, that should do a decent job with dispersion forces
Paolo On Wed, Dec 2, 2020 at 10:13 PM Stefano Baroni <[email protected]> wrote: > Besides, intermolecular distances in a molecular crystal sensitively > depend on the XC functional, all of which have a hard time properly > accounting for dispersion forces (some of them a worse time than others). SB > > On 2 Dec 2020, at 19:38, Claudio A. Perottoni <[email protected]> wrote: > > Dear Corrado, > > The ecutwfc in your input file seems a bit small. You may try using > https://www.materialscloud.org/work/tools/qeinputgenerator to generate an > input file for optimizing the crystal structure of your compound. > Best regards, > Claudio > > > On Wed, Dec 2, 2020 at 3:15 PM Cuocci Corrado <[email protected]> > wrote: > >> I have determined the crystal structure of new organic compound from >> X-ray powder diffraction data. >> >> First of all, I used quantum espresso to validate my new structure in a >> 'relax' calculation obtaining a result in a good agreement with the >> experimental structure. >> >> In a second step I tried to perform a 'vc-relax' but in this case the >> result seems chemically unreasonable: I observed a large variation of >> the cell parameters, final density too high for this type of compound, >> short intermolecular distances. >> Input and output files can be downloaded from: >> https://cloud.ba.cnr.it/index.php/s/5RmA7MqA9gJeRdx/download >> https://cloud.ba.cnr.it/index.php/s/qmnAwM5JeqDnHdG/download >> >> My experience in the use of the program is limited and I suspect I have >> made some mistakes. >> Do you have any suggestions to improve the calculation? >> >> Thanks a lot. >> Corrado >> -- >> ============================================ >> Cuocci Corrado >> Istituto di Cristallografia - CNR >> Via G. Amendola,122/o >> 70126 Bari (Italy) >> tel: +390805929161 >> fax:+390805929170 >> [email protected] >> ============================================ >> _______________________________________________ >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >> users mailing list [email protected] >> https://lists.quantum-espresso.org/mailman/listinfo/users >> > > > -- > > *Claudio A. Perottoni* > > Universidade de Caxias do Sul > 95070-560 Caxias do Sul - RS - Brazil > http://www.researcherid.com/rid/B-8409-2008 > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users > > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list [email protected] > 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
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