Thanks Giuseppe. Nandan.
On Wed, Feb 7, 2018 at 5:49 AM, Giuseppe Mattioli < giuseppe.matti...@ism.cnr.it> wrote: > > > Or just shifting the atoms slightly before starting the relaxation? > > Yes! If the code finds a starting symmetry, it does not break it. > > HTH > Giuseppe > > > Quoting Nandan Tandon <nandan.tan...@gmail.com>: > > > Hi, > > > > I am trying to relax a vacancy in a cubic 512 atom unit cell of diamond. > It > > has > > been seen that the T_d symmetry around the vacancy is lowered to D_{2d}. > > But my system does not show this because all the atoms (first 4 > neighbors) > > around the vacancy are at identical distances from the vacancy and each > > other. > > > > Initially, using a FCC supercell also gave the same relaxed structure. > This > > prompted me to start with a cubic structure. > > > > > > My question is, is there a trick to do such vacancy calculations? > > > > Like starting by substituting a carbon atom with another atom to distort > > the lattice > > before creating a vacancy at the site? > > > > Or just shifting the atoms slightly before starting the relaxation? > > > > I have done few tests to ensure that the Ecut is high (80Ryd), its a > Gamma > > point calculation, LDA potentials and an optimized lattice constant. > > > > Thanks and regards, > > > > Nandan. > > -- > > ************************************************************ > *********************************** > > Nandan Tandon > > Michigan State University > > East Lansing > > Michigan 48824-1226 > > ************************************************************ > ************************************* > > > > GIUSEPPE MATTIOLI > CNR - ISTITUTO DI STRUTTURA DELLA MATERIA > Via Salaria Km 29,300 - C.P. 10 > I-00015 - Monterotondo Scalo (RM) > Mob (*preferred*) +39 373 7305625 > Tel + 39 06 90672342 - Fax +39 06 90672316 > E-mail: <giuseppe.matti...@ism.cnr.it> > > _______________________________________________ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > -- *********************************************************************************************** Nandan Tandon Michigan State University East Lansing Michigan 48824-1226 *************************************************************************************************
_______________________________________________ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum