N.B., in the 16 version if you reduce the GREED to 0.1 it does what people think reducing the mixing factor does (in the unwritten literature). It does not do it the way people think, this there are many misconceptions in the literature about mixing. The latest version does this by turning on a set of internal switches such as SLOW so it is less greedy. This may help with your problem.
On Fri, Jan 20, 2017 at 3:16 PM, Laurence Marks <l-ma...@northwestern.edu> wrote: > I can provide some partial responses, although there are also some things > that I don't understand. Some of this (maybe most) is not the mixer but in > other parts of Wien2k. > > First, the old (2008) version is there if you use MSEC1, but I have not > tested it and it may fail. Better is to use MSEC3 which is almost the old > version. For some classes of problems this is more stable than MSR1, and > works better. If you are talking about the pre-multisecant version (BROYD) > that vanished some time ago. > > Second, there is a nasty "feature" particularly for +U (eece) cases, which > is partially discussed in the mixer Readme. There is no guarantee that a > solution exists -- the KS theorem is for densities but U is an orbital > term. It is very possible to have cases where there is no fixed-point > solution. The older MSEC1 (maybe BROYD) could find a fake solution where > the density was consistent but the orbital potential was not. The latest > version is much better in avoiding them and going for "real" solutions > rather than being trapped. For orbital potentials it is very important to > look at :MV to check that one really has a self-consistent orbital > potential. > > Third, there are cases where PBE (and all the GGA's in Wien2k that I have > tested) give unphysical results when applied to isolated d or f electrons > as done for -eece. I guess that the GGA functionals were not designed for > the densities of just high L orbitals. This leads to very bad behavior of > the mixing. I know of no way to solve this in the mixer, it is a structural > problem. It goes away if LDA is used as the form for VXC in -eece. > > Fourth, larger problem with low symmetry (P1 in particular) can certainly > behave badly. Part of this might be "somewhere" in Wien2k coding, part of > it is generic to a low symmetry problem. In many cases these have small > eigenvalues in the mixing Jacobian which are removed when symmetry is > imposed. All one can do is use MSEC3 or some of the additional flags (see > the mixer README) such as "SLOW". > > Fifth...probably exists, but I can't think of it immediately. > > On Fri, Jan 20, 2017 at 2:03 PM, Xavier Rocquefelte < > xavier.rocquefe...@univ-rennes1.fr> wrote: > >> Dear Colleagues >> >> I did recently a calculation which has been published long time ago >> using a old WIEN2k version (in 2008). >> >> It corresponds to a spin-polarized calculation for the compound CuO. The >> symmetry is removed and the idea is to estimate the total energies for >> different magnetic orders to extract magnetic couplings from a mapping >> analysis. Such calculations were converging fastly without any trouble >> in 2008. >> >> Here I have started from the scratch with a case.cif file to generate >> the case.struct file and initializing the calculation in a standard >> manner. >> >> Then I wanted to have the energy related to a ferromagnetic situation >> (not the more stable). I have 8 copper sites in the unit cell I am using. >> >> When this calculation is done using PBE+U everything goes fine. However >> when PBE0 hybrid on-site functional is used we observed oscillations and >> the magnetic moment disappear, which is definitely not correct. It >> should be mentionned that the convergency is really bad. If we do a >> similar calculation on the cristallographic unit cell (2 copper sites >> only) the calculations converge both in PBE+U and PBE0. >> >> The convergency problems only arises for low-symmetry and high number of >> magnetic elements. I didn't have such problems before and I wonder if we >> could still use old mixer scheme in such situations. Looking at the >> userguide, it seems that the mixer does not allow to do as before and >> PRATT mixer is too slow. >> >> Did you encounter similar difficulties (which were not in older WIEN2k >> versions)? >> >> Best Regards >> >> Xavier >> >> Here is the case.struct: >> >> blebleble >> P LATTICE,NONEQUIV.ATOMS: 16 1_P1 >> MODE OF CALC=RELA unit=bohr >> 14.167163 6.467777 11.993298 90.000000 95.267000 90.000000 >> ATOM -1: X=0.87500000 Y=0.75000000 Z=0.87500000 >> MULT= 1 ISPLIT= 8 >> Cu NPT= 781 R0=0.00005000 RMT= 1.9700 Z: 29.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -2: X=0.12500000 Y=0.25000000 Z=0.62500000 >> MULT= 1 ISPLIT= 8 >> Cu NPT= 781 R0=0.00005000 RMT= 1.9700 Z: 29.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -3: X=0.12500000 Y=0.25000000 Z=0.12500000 >> MULT= 1 ISPLIT= 8 >> Cu NPT= 781 R0=0.00005000 RMT= 1.9700 Z: 29.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -4: X=0.87500000 Y=0.75000000 Z=0.37500000 >> MULT= 1 ISPLIT= 8 >> Cu NPT= 781 R0=0.00005000 RMT= 1.9700 Z: 29.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -5: X=0.62500000 Y=0.25000000 Z=0.62500000 >> MULT= 1 ISPLIT= 8 >> Cu NPT= 781 R0=0.00005000 RMT= 1.9700 Z: 29.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -6: X=0.37500000 Y=0.75000000 Z=0.87500000 >> MULT= 1 ISPLIT= 8 >> Cu NPT= 781 R0=0.00005000 RMT= 1.9700 Z: 29.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -7: X=0.37500000 Y=0.75000000 Z=0.37500000 >> MULT= 1 ISPLIT= 8 >> Cu NPT= 781 R0=0.00005000 RMT= 1.9700 Z: 29.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -8: X=0.62500000 Y=0.25000000 Z=0.12500000 >> MULT= 1 ISPLIT= 8 >> Cu NPT= 781 R0=0.00005000 RMT= 1.9700 Z: 29.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -9: X=0.87500000 Y=0.41840000 Z=0.62500000 >> MULT= 1 ISPLIT= 8 >> O NPT= 781 R0=0.00010000 RMT= 1.6900 Z: 8.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -10: X=0.12500000 Y=0.91840000 Z=0.87500000 >> MULT= 1 ISPLIT= 8 >> O NPT= 781 R0=0.00010000 RMT= 1.6900 Z: 8.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -11: X=0.12500000 Y=0.58160000 Z=0.37500000 >> MULT= 1 ISPLIT= 8 >> O NPT= 781 R0=0.00010000 RMT= 1.6900 Z: 8.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -12: X=0.87500000 Y=0.08160000 Z=0.12500000 >> MULT= 1 ISPLIT= 8 >> O NPT= 781 R0=0.00010000 RMT= 1.6900 Z: 8.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -13: X=0.62500000 Y=0.58160000 Z=0.87500000 >> MULT= 1 ISPLIT= 8 >> O NPT= 781 R0=0.00010000 RMT= 1.6900 Z: 8.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -14: X=0.37500000 Y=0.08160000 Z=0.62500000 >> MULT= 1 ISPLIT= 8 >> O NPT= 781 R0=0.00010000 RMT= 1.6900 Z: 8.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -15: X=0.37500000 Y=0.41840000 Z=0.12500000 >> MULT= 1 ISPLIT= 8 >> O NPT= 781 R0=0.00010000 RMT= 1.6900 Z: 8.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> ATOM -16: X=0.62500000 Y=0.91840000 Z=0.37500000 >> MULT= 1 ISPLIT= 8 >> O NPT= 781 R0=0.00010000 RMT= 1.6900 Z: 8.0 >> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 >> 0.0000000 1.0000000 0.0000000 >> 0.0000000 0.0000000 1.0000000 >> 1 NUMBER OF SYMMETRY OPERATIONS >> 1 0 0 0.00000000 >> 0 1 0 0.00000000 >> 0 0 1 0.00000000 >> 1 >> >> _______________________________________________ >> Wien mailing list >> Wien@zeus.theochem.tuwien.ac.at >> https://urldefense.proofpoint.com/v2/url?u=http-3A__zeus.the >> ochem.tuwien.ac.at_mailman_listinfo_wien&d=CwICAg&c=yHlS04Hh >> Braes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4r >> nxTj8IUxm818jnvqKFdqWLwmqg0&m=2XKWFhupuwNnAG_KMjoPsmaknSsM7d >> ZHIYk6PeNkTHI&s=e_j2nM5dAAeol3fy52jir16AbaPkAQFlNIRahgZuEvQ&e= >> SEARCH the MAILING-LIST at: https://urldefense.proofpoint. >> com/v2/url?u=http-3A__www.mail-2Darchive.com_wien-40zeus. >> theochem.tuwien.ac.at_index.html&d=CwICAg&c=yHlS04HhBraes5 >> BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818 >> jnvqKFdqWLwmqg0&m=2XKWFhupuwNnAG_KMjoPsmaknSsM7dZHIYk6PeNkTHI&s= >> wt8xEGslBsZBo5wAnOmDWSoJb1h-Ead_WGbqDy456EI&e= >> > > > > -- > Professor Laurence Marks > "Research is to see what everybody else has seen, and to think what nobody > else has thought", Albert Szent-Gyorgi > www.numis.northwestern.edu ; Corrosion in 4D: > MURI4D.numis.northwestern.edu > Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent > Co-Editor, Acta Cryst A > -- Professor Laurence Marks "Research is to see what everybody else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi www.numis.northwestern.edu ; Corrosion in 4D: MURI4D.numis.northwestern.edu Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent Co-Editor, Acta Cryst A
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