> 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 <[email protected]>: > 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: <[email protected]> _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
