Dear Oleg, I am attaching the structure files which I have used for the calculation. I have used similar procedure as given for BaTiO3 tutorial (same parameters for initialising and same k-point mesh for Berrypi. The calculated polarisation for cubic phase is very low. So so spontaneous polarisation is still very low as given in my previous mail. I am unable to trace my mistakes.
Best regards Lokanath On Wed, May 2, 2018 at 7:25 PM, Oleg Rubel <rub...@mcmaster.ca> wrote: > Dear Lokanath, > > PbTiO3 was one of compounds used in the test of BerryPI (see Table 3 in > http://olegrubel.mcmaster.ca/publications/2013/Ahmed_CPC_184_2013.pdf). I > think you should also compute polarization in the cubic structure of PbTiO3 > even though they are deemed to have no polarization. If this does not help, > I would suggest looking into the structure more carefully, tetragonal > distortion, compare with experiment, etc. > > > I hope it will help > Oleg > > -- > Oleg Rubel (PhD, PEng) > Department of Materials Science and Engineering > McMaster University > JHE 359, 1280 Main Street West, Hamilton, Ontario L8S 4L8, Canada > <https://maps.google.com/?q=359,+1280+Main+Street+West,+Hamilton,+Ontario+L8S+4L8,+Canada&entry=gmail&source=g> > Email: rub...@mcmaster.ca > Tel: +1-905-525-9140, ext. 24094 > Web: http://olegrubel.mcmaster.ca > > On 2018-May-02 08:38, Lokanath Patra wrote: > >> Dear all, >> >> I am using Berry phase tutorial to calculate the polarization of PbTiO3. >> I have followed the BaTiO3 tutorial. I have two structures, one is >> tetragonal (non-centrosymmetric) and the second one is cubic >> (centrosymmetric). I have calculated the (spontaneous) polarization >> as 1.189769e-01 C/m2 (as the cubic system doesn't posses any polarization) >> which is very low as the reported values are around 80 to 100 µC/cm2. >> Please help me. >> >> Regards >> Lokanath >> >> -- >> Lokanath Patra >> Ph.D Scholar >> Dept. of Physics >> School of Applied and Basic Sciences >> Central University of Tamil Nadu >> Thiruvarur >> Tamil Nadu - 610004 >> Ph no - +91-8675834507 >> >> ------------------------------------------------------------------------ >> >> Central University of Tamil Nadu is in not responsible for the contents >> of this email. The sender takes responsibility for the content of this >> email. /This mail is also governed by the relevant disclaimer policies >> of Central University of Tamil Nadu. >> <http://cutn.ac.in/disclaimer.php>/ >> >> >> _______________________________________________ >> Wien mailing list >> Wien@zeus.theochem.tuwien.ac.at >> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> SEARCH the MAILING-LIST at: http://www.mail-archive.com/wi >> e...@zeus.theochem.tuwien.ac.at/index.html >> >> _______________________________________________ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: http://www.mail-archive.com/wi > e...@zeus.theochem.tuwien.ac.at/index.html > -- Lokanath Patra Ph.D Scholar Dept. of Physics School of Applied and Basic Sciences Central University of Tamil Nadu Thiruvarur Tamil Nadu - 610004 Ph no - +91-8675834507 -- Central University of Tamil Nadu is in not responsible for the contents of this email. The sender takes responsibility for the content of this email. This mail is also governed by the relevant disclaimer policies of Central University of Tamil Nadu. <http://cutn.ac.in/disclaimer.php>
tet1.struct
Description: Binary data
cubic.struct
Description: Binary data
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