Supercell will NEVER reduce the unit cell parameters. Probably you did it already in your first Au calculations !
Did you optimize the volume ?? After optimize.job the struct file contains the lattice parameters from your "last" calculation! PS: I don_t know what you want to simulate, but a 8-atom cell is way too small to simulate an "impurity". On 01/12/2013 10:06 PM, Robert Larson wrote: > Thanks very much for you help, I have made the changes that you suggested. > > In a related calculation, I created a supercell of a gold lattice and > introduced a chromium atom in order to model chromium atoms in > substitutional sites. I followed the guidelines in the users guide and > everything in the calculation seemed to go well. However I noticed that > the a, b and c parameters had been slightly reduced (around 5%) from the > values that I had entered originally. Am I correct in thinking that this > adjustment was made to account for the new lattice configuration? I have > attached the struct file from the calculation. > > Thanks again in advance, > Bob Larson > > > On Mon, Jan 7, 2013 at 3:38 AM, Peter Blaha > <pblaha at theochem.tuwien.ac.at <mailto:pblaha at theochem.tuwien.ac.at>> > wrote: > > I checked your scf and struct files: > > a) Please use identical RMT for Ru for the 2 cases. Since RuO2 > forces you to have r(Ru)=2.0), use it also for hcp-Ru. > (I don't think the effect will be very large, but ...) > > b) You cannot do these calculations with just ONE k-point ! > For metallic Ru you should use something like "10000" when running > x kgen; > and since also RuO2 is metallic, use a similar number (maybe 5000, since > RuO2 contains more atoms/cell than Ru). > > c) Finally, check how much the differences in :RTO depend on > RKMAX (case.in1; 7 by default). Once you have the first scf-calculation > saved, increase it to 8, do another run_lapw and compare the > resulting RTO > > The possible errors are not so easy to quantify. Besides computational > parameters (which you can check as mentioned above), the error from > DFT is hard to quantify and only from experience for a certain > quantity in comparison with experiment we can estimate it. > >From my experience with Isomer shifts in Fe (M?ssbauer), it should > be ok within 10-20 %, but it could be different for Ru .... > > > > ForwardedMessage.eml > Subject: > Electron density at ruthenium nucleus > From: > Robert Larson <rolarson at mymail.mines.edu > <mailto:rolarson at mymail.mines.edu>> > Date: > 01/05/2013 06:13 PM > To: > wien at zeus.theochem.tuwien.ac.__at > <mailto:wien at zeus.theochem.tuwien.ac.at> > > > Hello, > I would like to compare the change in electron density at the > nucleus of a ruthenium atom in an Ru crystal versus in (rutile) > ruthenium oxide, RuO2. This is for Ru97 electron capture decay half > life predictions. > > I am seeing a difference of 0.02% for total electron density by > comparing the :RTO001 values for each case -- which agrees well with > experimental data. I have attached the struct and scf files for > each case. > > My questions are 1) do these calculations look reasonable? and 2) > what would an estimate be for the uncertainty of :RTO electron > density values? > > I am running WIEN2k_12.1 (Release 22/7/2012) under mac OSX 10.8.2 > and Intel Fortran composer_xe_2011_sp1.9.289. > > Thanks very much, > Robert Larson > Colorado School of Mines > Golden, CO > > -- > > P.Blaha > > ------------------------------__------------------------------__-------------- > Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna > Phone: +43-1-58801-165300 <tel:%2B43-1-58801-165300> > FAX: +43-1-58801-165982 <tel:%2B43-1-58801-165982> > Email: blaha at theochem.tuwien.ac.at > <mailto:blaha at theochem.tuwien.ac.at> WWW: > http://info.tuwien.ac.at/__theochem/ > <http://info.tuwien.ac.at/theochem/> > > ------------------------------__------------------------------__-------------- > _________________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.__at > <mailto:Wien at zeus.theochem.tuwien.ac.at> > http://zeus.theochem.tuwien.__ac.at/mailman/listinfo/wien > <http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien> > > > > > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > -- P.Blaha -------------------------------------------------------------------------- Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna Phone: +43-1-58801-165300 FAX: +43-1-58801-165982 Email: blaha at theochem.tuwien.ac.at WWW: http://info.tuwien.ac.at/theochem/ --------------------------------------------------------------------------