As Peter said, do NOT simply reduce the greed, it does not work the same as it does in PP calculations.
More to the point, you/we need more information to know what is going on. Assuming that you are using the latest version (or similar) then grep -e :DIR -e GREED -e :FRMS -e :ENE -e :CHARG -e PRATT -e :DIS -e "MIXING SC" -e PLANE *.scf | tail -40 will give more information and what is really going on... On Mon, Apr 25, 2011 at 2:21 PM, Peter Blaha <pblaha at theochem.tuwien.ac.at> wrote: > The convergence behaviour is not very good, but it is not too bad either. > > Check also :MMT or some :MMI0xx > > For more complicated cases (metallic ??) it is well possible that one needs > more > than 40 iterations. Thus my suggestion is to keep going and submit another > job. > > Sometimes it is better to keep the history (use -NI switch), sometimes it > can also > be better to remove the history (rm *.broy*; which will be done > automatically when > -NI is not supplied). > > The mixing parameter has little importance with MSEC1, but still, a too > small mixing > can lead to too small steps and thus "pseudoconvergence" (this simply means, > that so > little new density is mixed, that eg. the total energy is not changing and > one thinks > the calculation is converged). > > PRATT is most likely "useless" for your problem. > > In LDA+U calculations it is easily possible to reach different states > (different > orbital occupations), which are stable and local minima. Once you have > reached > convergence, there is never a guarantee that this is the groundstate and > really > has the lowest energy. > The suggested procedure in the UG is NOT ALWAYS leading to the lowest state, > but often it will do. > > >> I have searched the list but I'm a bit confused with the posts, so I'll >> pose my questions here. >> >> I am running LDA+U with and without spin-orbit coupling for a structure in >> a cell with the following cell parameters (Bohr): >> >> P ? LATTICE,NONEQUIV.ATOMS: 14127_P4/mbm >> MODE OF CALC=RELA >> ?10.353171 10.353171 43.972470 90.000000 90.000000 90.000000 >> >> and a cell sampling of 12x12x3, which gives 432 points in the BZ, 42 in >> the IBZ. My RKMAX is 8 - it was necessary to go to such high values to >> converge the spin moment of >> the system, as well as the energy down to 1 mRy. I followed the procedure >> stated in the manual: started with the LSDA calculation, then included >> spin-orbit coupling and now >> I am including the U gradually (well, at this point, just trying to...). I >> have to get to U=4 eV, so I'm growing it in steps of 1 eV. >> >> Convergence was very good for the LSDA+U calculations without SOC, and >> they have finished, already (that is, I have already gotten to the 4 eV in >> U). However, I am having >> problems converging the scf, with the charge and energy distances (as >> obtained by grep convergence case.dayfile) oscillating, and never attaining >> convergence, which I set >> to ec=0.00001 and cc=0.0001 (the numbers are appended by the end of this >> message). More than 40 SCF steps have passed. >> >> Usually, in pseudopotential calculations, one possible solution is to >> decrease the mixing weight of the charge densities for the following SCF >> step, and the other is to >> increase the smearing temperature. I would like to tweak with the mixing >> rather than increasing the temperature, if possible, because from my >> experience, increasing the >> temperature can sometimes lead to a non-magnetic state. However, I see >> from the mailing list that (at least in LAPW calculations), too small a >> mixing can lead to >> pseudo-convergence - which I don't understand what is. So, my questions >> are the following: >> >> 1) What is the best thing to do to make my calculation converge: increase >> the mixing, or to diminish it? Should I change the mixing for MSEC1, and if >> so, by which amount? >> Or, would it be good to change to PRATT, instead? I am quite lost with >> regards to that. >> 2) Would the application of SOC to the already converged LSDA+U >> calculation yield too different results from starting from a converged >> LSDA+SOC with later inclusion of U? >> 3) What is the pseudo-convergence mentioned in previous emails in the >> list? >> >> Of course, I will gladly provide more information, if needed. >> >> Best regards, >> >> Marcos >> Universidad de Cantabria, Spain >> >> ======================================= >> >> Convergence of energy and charge distances: >> >> :ENERGY convergence: ?0 0.00001 .0002941150000000 >> :CHARGE convergence: ?0 0.0001 .0088826 >> :ENERGY convergence: ?0 0.00001 .0000916950000000 >> :CHARGE convergence: ?0 0.0001 .0085946 >> :ENERGY convergence: ?0 0.00001 .0000428400000000 >> :CHARGE convergence: ?0 0.0001 .0112915 >> :ENERGY convergence: ?0 0.00001 .0001772500000000 >> :CHARGE convergence: ?0 0.0001 .0113780 >> :ENERGY convergence: ?0 0.00001 .0002456850000000 >> :CHARGE convergence: ?0 0.0001 .0104415 >> :ENERGY convergence: ?0 0.00001 .0001420300000000 >> :CHARGE convergence: ?0 0.0001 .0083852 >> :ENERGY convergence: ?0 0.00001 .0000500150000000 >> :CHARGE convergence: ?0 0.0001 .0084675 >> :ENERGY convergence: ?0 0.00001 .0001809700000000 >> :CHARGE convergence: ?0 0.0001 .0134776 >> :ENERGY convergence: ?0 0.00001 .0001993400000000 >> :CHARGE convergence: ?0 0.0001 .0112308 >> :ENERGY convergence: ?0 0.00001 .0002392700000000 >> :CHARGE convergence: ?0 0.0001 .0104208 >> :ENERGY convergence: ?0 0.00001 .0002088150000000 >> :CHARGE convergence: ?0 0.0001 .0069138 >> :ENERGY convergence: ?0 0.00001 .0001630050000000 >> :CHARGE convergence: ?0 0.0001 .0109876 >> :ENERGY convergence: ?0 0.00001 .0002176700000000 >> :CHARGE convergence: ?0 0.0001 .0012609 >> :ENERGY convergence: ?0 0.00001 .0001806300000000 >> :CHARGE convergence: ?0 0.0001 .0042825 >> :ENERGY convergence: ?0 0.00001 .0000720450000000 >> :CHARGE convergence: ?0 0.0001 .0045301 >> :ENERGY convergence: ?0 0.00001 .0000129050000000 >> :CHARGE convergence: ?0 0.0001 .0011304 >> :ENERGY convergence: ?0 0.00001 .0002283150000000 >> :CHARGE convergence: ?0 0.0001 .0047456 >> :ENERGY convergence: ?0 0.00001 .0003098100000000 >> :CHARGE convergence: ?0 0.0001 .0100820 >> :ENERGY convergence: ?0 0.00001 .0003708750000000 >> :CHARGE convergence: ?0 0.0001 .0087276 >> :ENERGY convergence: ?0 0.00001 .0000788950000000 >> :CHARGE convergence: ?0 0.0001 .0090876 >> :ENERGY convergence: ?0 0.00001 .0000849050000000 >> :CHARGE convergence: ?0 0.0001 .0093747 >> :ENERGY convergence: ?0 0.00001 .0000842350000000 >> :CHARGE convergence: ?0 0.0001 .0079561 >> :ENERGY convergence: ?0 0.00001 .0000553500000000 >> :CHARGE convergence: ?0 0.0001 .0122027 >> :ENERGY convergence: ?0 0.00001 .0000434050000000 >> :CHARGE convergence: ?0 0.0001 .0109352 >> :ENERGY convergence: ?0 0.00001 .0000227750000000 >> :CHARGE convergence: ?0 0.0001 .0122136 >> :ENERGY convergence: ?0 0.00001 .0000194300000000 >> :CHARGE convergence: ?0 0.0001 .0121261 >> :ENERGY convergence: ?0 0.00001 .0000292700000000 >> :CHARGE convergence: ?0 0.0001 .0131197 >> :ENERGY convergence: ?0 0.00001 .0000360650000000 >> :CHARGE convergence: ?0 0.0001 .0110031 >> :ENERGY convergence: ?0 0.00001 .0000300950000000 >> :CHARGE convergence: ?0 0.0001 .0115123 >> :ENERGY convergence: ?0 0.00001 .0000323600000000 >> :CHARGE convergence: ?0 0.0001 .0099887 >> :ENERGY convergence: ?0 0.00001 .0000147550000000 >> :CHARGE convergence: ?0 0.0001 .0110331 >> :ENERGY convergence: ?0 0.00001 .0001196200000000 >> :CHARGE convergence: ?0 0.0001 .0005253 >> >> >> >> _______________________________________________ >> Wien mailing list >> Wien at zeus.theochem.tuwien.ac.at >> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > > -- > ----------------------------------------- > Peter Blaha > Inst. Materials Chemistry, TU Vienna > Getreidemarkt 9, A-1060 Vienna, Austria > Tel: +43-1-5880115671 > Fax: +43-1-5880115698 > email: pblaha at theochem.tuwien.ac.at > ----------------------------------------- > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > -- Laurence Marks Department of Materials Science and Engineering MSE Rm 2036 Cook Hall 2220 N Campus Drive Northwestern University Evanston, IL 60208, USA Tel: (847) 491-3996 Fax: (847) 491-7820 email: L-marks at northwestern dot edu Web: www.numis.northwestern.edu Chair, Commission on Electron Crystallography of IUCR www.numis.northwestern.edu/ Research is to see what everybody else has seen, and to think what nobody else has thought Albert Szent-Gyorgi