<html><body><p>Dear Martin, </p><p>Thank you for your suggestions and reminding me of the work of </p><p>Stefaan. I try again with this in mind. </p><p>Thanks</p><p>Tomas </p><br><blockquote>Dear Tomas,<br><br>at the moment I do not see something being obviously suspicious. Maybe <br>the culprit is some structural phase transition invalidating the <br>experimental structure you compare with. You might get one or two ideas <br>from Stefaan Cottenier's work?<br><br>Error Estimates for Solid-State Density-Functional<br>Theory Predictions: An Overview by Means of the<br>Ground-State Elemental Crystals<br>K. Lejaeghere , V. Van Speybroeck , G. Van Oost & S. Cottenier<br><br>http://dx.doi.org/10.1080/10408436.2013.772503<br><br>Best regards,<br><br>Martin<br><br><br>---<br>Dr. Martin Pieper<br>Karl-Franzens University<br>Institute of Physics<br>Universitätsplatz 5<br>A-8010 Graz<br>Austria<br>Tel.: +43-(0)316-380-8564<br><br><br>Am 10.11.2015 13:05, schrieb Tomas Kana:<br>> Dear Martin and Gerhard,<br>> <br>> Thank you for your suggestions. Gerhard, thank you for mentioning this<br>> <br>> <br>> experimental work. Will you please send me the pdf<br>> <br>> of the article? I do not have access to it.<br>> <br>> Regarding Martin's questions:<br>> <br>> I tried to include magnetism<br>> <br>> of the constituents by performing spin polarized calculations, too,<br>> <br>> but the equilbrium volume was the same. The forces within the<br>> hexagonal unit cell<br>> <br>> were not given in case.scf (I think there was too much symmetry<br>> operations).<br>> <br>> However, I recently tried to express the hexagonal unit cell in a<br>> orthorhombic base<br>> <br>> and cancel the symmetry operations by using inequivalent atoms<br>> <br>> (I send the structure file in attachment). The volume was still wrong<br>> but<br>> <br>> I know the values of the forces. For the experimental<br>> <br>> atomic volume they were at most 0.84 mRy/a.u.<br>> <br>> With best regards<br>> <br>> Tomas Kana<br>> <br>>> Since you ask for ideas and without really looking at the problem:<br>>> Assuming that the experimental numbers are correct, is this a room<br>>> temperature structure? The calculations are, of course, ground state<br>>> <br>>> zero Kelvin, so things might go south if there is a phase transition<br>>> <br>>> somewhere. Considering the elements you deal with maybe magnetic?<br>>> What<br>>> are the forces in your calculations?<br>>> <br>>> Good luck,<br>>> <br>>> Martin<br>> <br>> _______________________________________________<br>> Wien mailing list<br>> Wien@zeus.theochem.tuwien.ac.at<br>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien<br>> SEARCH the MAILING-LIST at:<br>> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html<br>_______________________________________________<br>Wien mailing list<br>Wien@zeus.theochem.tuwien.ac.at<br>http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien<br>SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html</blockquote></body></html>