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 > <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] > <mailto:[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/5RmA7MqA9gJeRdx/download> > https://cloud.ba.cnr.it/index.php/s/qmnAwM5JeqDnHdG/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] <mailto:[email protected]> > ============================================ > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu > <http://www.max-centre.eu/>) > users mailing list [email protected] > <mailto:[email protected]> > https://lists.quantum-espresso.org/mailman/listinfo/users > <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 > <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
