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convergence for optB88-vdW calculations

Posted: Wed Dec 11, 2013 11:11 pm
by wji
Hi,

I've been doing vdW-DF calculations with different exchange functionals, like optPBE, optB88, revPBE, optB86b, for molecules adsorbed on Cu surfaces. It seems that I cannot get those optB88 runs converged, but the same set of input, namely POSCAR/POTCAR/KPOTINS, works perfectly with optPBE, revPBE, and optB86b.

The OSZICAR reads like,
RMM: 1 0.184167647837E+05 0.18417E+05 -0.77110E+05 1388 0.155E+03
RMM: 2 0.414238239981E+04 -0.14274E+05 -0.16370E+05 1388 0.340E+02
RMM: 3 0.128064378562E+04 -0.28617E+04 -0.29815E+04 1388 0.213E+02
RMM: 4 0.170458835310E+03 -0.11102E+04 -0.45700E+03 1388 0.102E+02
RMM: 5 -0.933833675321E+02 -0.26384E+03 -0.17355E+03 1388 0.561E+01
RMM: 6 -0.202369477127E+03 -0.10899E+03 -0.86458E+02 1388 0.437E+01
RMM: 7 -0.251288003314E+03 -0.48919E+02 -0.42862E+02 1388 0.282E+01
RMM: 8 -0.273064795431E+03 -0.21777E+02 -0.20440E+02 1388 0.213E+01
RMM: 9 -0.290411651985E+03 -0.17347E+02 -0.17333E+02 3746 0.136E+01
RMM: 10 -0.290870941005E+03 -0.45929E+00 -0.91764E+00 3124 0.284E+00
RMM: 11 -0.290946446679E+03 -0.75506E-01 -0.68072E-01 3668 0.573E-01
RMM: 12 -0.290948367184E+03 -0.19205E-02 -0.19187E-02 2897 0.132E-01 0.111E+02
RMM: 13 -0.171282433314E+03 0.11967E+03 -0.25110E+03 2785 0.104E+02 0.616E+01
RMM: 14 -0.947662672783E+02 0.76516E+02 -0.42107E+02 2777 0.462E+01 0.799E+00
RMM: 15 -0.971390290832E+02 -0.23728E+01 -0.12842E+01 2834 0.583E+00 0.786E+00
RMM: 16 -0.976519940989E+02 -0.51297E+00 -0.25141E+00 2784 0.288E+00 0.380E+00
RMM: 17 -0.981948571860E+02 -0.54286E+00 -0.75732E-01 2801 0.148E+00 0.143E+00
RMM: 18 -0.985291673822E+02 -0.33431E+00 -0.15374E-01 2821 0.604E-01 0.787E-01
RMM: 19 -0.987683487684E+02 -0.23918E+00 -0.62288E-02 2797 0.436E-01 0.695E-01
RMM: 20 -0.988748389221E+02 -0.10649E+00 -0.23841E-02 2783 0.259E-01 0.399E-01
RMM: 21 -0.989086596402E+02 -0.33821E-01 -0.24642E-02 2787 0.246E-01 0.259E-01
RMM: 22 -0.988491962993E+02 0.59463E-01 -0.44320E-03 2783 0.984E-02 0.858E-02
RMM: 23 -0.988320348916E+02 0.17161E-01 -0.18322E-02 3027 0.110E-01 0.822E-02
RMM: 24 -0.988284134408E+02 0.36215E-02 -0.24756E-02 2728 0.121E-01 0.824E-02
RMM: 25 -0.988288192144E+02 -0.40577E-03 -0.65854E-03 2690 0.800E-02 0.639E-02
RMM: 26 -0.988322849491E+02 -0.34657E-02 -0.54124E-03 2696 0.711E-02 0.199E-02
RMM: 27 -0.988257393482E+02 0.65456E-02 0.72921E-02 4548 0.185E-01 0.187E-02
RMM: 28 -0.987986109018E+02 0.27128E-01 -0.35517E-01 4176 0.584E-01 0.380E-02
RMM: 29 -0.988317740631E+02 -0.33163E-01 -0.37914E-01 2784 0.452E-01 0.188E-02
RMM: 30 -0.988346770389E+02 -0.29030E-02 -0.27038E-02 3265 0.170E-01 0.159E-02
RMM: 31 -0.988355105863E+02 -0.83355E-03 -0.16619E-02 2760 0.110E-01 0.112E-02
RMM: 32 -0.988429974408E+02 -0.74869E-02 -0.43219E-02 2862 0.113E-01 0.119E-02
RMM: 33 -0.988388525989E+02 0.41448E-02 -0.55106E-02 2756 0.136E-01 0.855E-03
RMM: 34 -0.988402654590E+02 -0.14129E-02 -0.91962E-03 3558 0.104E-01 0.113E-02
RMM: 35 -0.988404461622E+02 -0.18070E-03 -0.83625E-03 3185 0.946E-02 0.766E-03
RMM: 36 -0.988410478441E+02 -0.60168E-03 -0.84963E-03 2741 0.855E-02 0.631E-03
RMM: 37 -0.988408996526E+02 0.14819E-03 -0.93331E-03 2722 0.781E-02 0.483E-03
RMM: 38 -0.988426223494E+02 -0.17227E-02 -0.17040E-02 2760 0.921E-02 0.498E-03
RMM: 39 -0.988418314866E+02 0.79086E-03 -0.31887E-02 2801 0.131E-01 0.482E-03
RMM: 40 -0.988409149325E+02 0.91655E-03 -0.13246E-02 2744 0.995E-02 0.371E-03


The energy difference jumps around 1E-3 but never falls into 1E-5. I've tried making AMIX and BMIX smaller or use Davidson for electronic minimization, and it didn't work. I also tried to reduce the optimization level of vdw_nl.F and xclib*.F when compiling, but it didn't work as well. I just wonder if there is a small bug for the optB88-vdW implementation in VASP?

Thanks a lot!

Wei


<span class='smallblacktext'>[ Edited ]</span>

Re: convergence for optB88-vdW calculations

Posted: Tue Sep 10, 2024 2:34 pm
by support_vasp

Hi,

We're sorry that we didn’t answer your question. This does not live up to the quality of support that we aim to provide. The team has since expanded. If we can still help with your problem, please ask again in a new post, linking to this one, and we will answer as quickly as possible.

Best wishes,

VASP