Hello,
I am currently running TD-DFT calculations on multiple silicon quantum dots, using the DIIS_GDM algorithm. For the first time, I stumbled accross what seems like an SCF convergence issue, with the Si71H84 molecule (spheroidal shape, Td symmetry)
Here is the geometry, it was obtained through a Gaussian 16 geometry optimization with B3LYP/def2-TZVP:
$molecule 0 1 Si 2.564423983323 5.801276835919 2.564423983323 Si 5.801276835919 2.564423983323 2.564423983323 Si 2.564423983323 2.564423983323 5.801276835919 Si 4.127882545076 1.384809362379 1.384809362379 Si 1.384809362379 1.384809362379 4.127882545076 Si 1.384809362379 4.127882545076 1.384809362379 Si 2.771610583248 -0.001653148516 2.771610583248 Si 5.494442808983 -2.925524373593 2.925524373593 Si 2.925524373593 -2.925524373593 5.494442808983 Si 4.134899191666 -1.410360991400 4.134899191666 Si 4.134899191666 -4.134899191666 1.410360991400 Si 1.410360991400 -4.134899191666 4.134899191666 Si 1.382988496147 -1.382988496147 1.382988496147 Si 2.925524373593 -5.494442808983 2.925524373593 Si 2.925524373593 5.494442808983 -2.925524373593 Si 5.494442808983 2.925524373593 -2.925524373593 Si 2.771610583248 2.771610583248 -0.001653148516 Si 4.134899191666 4.134899191666 -1.410360991400 Si 4.134899191666 1.410360991400 -4.134899191666 Si 1.382988496147 1.382988496147 -1.382988496147 Si 1.410360991400 4.134899191666 -4.134899191666 Si 5.421908562296 0.000000000000 0.000000000000 Si 2.771610583248 0.001653148516 -2.771610583248 Si 5.801276835919 -2.564423983323 -2.564423983323 Si 2.771610583248 -2.771610583248 0.001653148516 Si 4.127882545076 -1.384809362379 -1.384809362379 Si 1.384809362379 -4.127882545076 -1.384809362379 Si 1.384809362379 -1.384809362379 -4.127882545076 Si 2.564423983323 -5.801276835919 -2.564423983323 Si 2.925524373593 2.925524373593 -5.494442808983 Si 2.564423983323 -2.564423983323 -5.801276835919 Si -2.925524373593 5.494442808983 2.925524373593 Si -0.001653148516 2.771610583248 2.771610583248 Si -2.925524373593 2.925524373593 5.494442808983 Si -1.410360991400 4.134899191666 4.134899191666 Si -1.382988496147 1.382988496147 1.382988496147 Si -4.134899191666 1.410360991400 4.134899191666 Si -4.134899191666 4.134899191666 1.410360991400 Si 0.000000000000 0.000000000000 5.421908562296 Si -2.771610583248 0.001653148516 2.771610583248 Si 0.001653148516 -2.771610583248 2.771610583248 Si -2.564423983323 -2.564423983323 5.801276835919 Si -1.384809362379 -1.384809362379 4.127882545076 Si -1.384809362379 -4.127882545076 1.384809362379 Si -4.127882545076 -1.384809362379 1.384809362379 Si -2.564423983323 -5.801276835919 2.564423983323 Si 0.000000000000 5.421908562296 0.000000000000 Si -2.564423983323 5.801276835919 -2.564423983323 Si 0.001653148516 2.771610583248 -2.771610583248 Si -2.771610583248 2.771610583248 0.001653148516 Si -1.384809362379 4.127882545076 -1.384809362379 Si -1.384809362379 1.384809362379 -4.127882545076 Si -4.127882545076 1.384809362379 -1.384809362379 Si 0.000000000000 0.000000000000 0.000000000000 Si -2.771610583248 -0.001653148516 -2.771610583248 Si -0.001653148516 -2.771610583248 -2.771610583248 Si -2.771610583248 -2.771610583248 -0.001653148516 Si -1.382988496147 -1.382988496147 -1.382988496147 Si -1.410360991400 -4.134899191666 -4.134899191666 Si -4.134899191666 -4.134899191666 -1.410360991400 Si -4.134899191666 -1.410360991400 -4.134899191666 Si 0.000000000000 -5.421908562296 0.000000000000 Si -2.925524373593 -5.494442808983 -2.925524373593 Si -2.564423983323 2.564423983323 -5.801276835919 Si 0.000000000000 0.000000000000 -5.421908562296 Si -2.925524373593 -2.925524373593 -5.494442808983 Si -5.494442808983 2.925524373593 2.925524373593 Si -5.801276835919 -2.564423983323 2.564423983323 Si -5.801276835919 2.564423983323 -2.564423983323 Si -5.421908562296 0.000000000000 0.000000000000 Si -5.494442808983 -2.925524373593 -2.925524373593 H 3.281169077705 6.648496194615 1.579323701234 H 3.544673966205 5.286275514187 3.544673966205 H 1.579323701234 6.648496194615 3.281169077705 H 5.286275514187 3.544673966205 3.544673966205 H 6.648496194615 3.281169077705 1.579323701234 H 6.648496194615 1.579323701234 3.281169077705 H 3.544673966205 3.544673966205 5.286275514187 H 3.281169077705 1.579323701234 6.648496194615 H 1.579323701234 3.281169077705 6.648496194615 H 6.000626673498 -3.914663193815 3.914663193815 H 6.678028071202 -2.298208202704 2.298208202704 H 2.298208202704 -2.298208202704 6.678028071202 H 3.914663193815 -3.914663193815 6.000626673498 H 4.996354434129 -0.553098808549 4.996354434129 H 4.996354434129 -4.996354434129 0.553098808549 H 0.553098808549 -4.996354434129 4.996354434129 H 2.298208202704 -6.678028071202 2.298208202704 H 3.914663193815 -6.000626673498 3.914663193815 H 2.298208202704 6.678028071202 -2.298208202704 H 3.914663193815 6.000626673498 -3.914663193815 H 6.678028071202 2.298208202704 -2.298208202704 H 6.000626673498 3.914663193815 -3.914663193815 H 4.996354434129 4.996354434129 -0.553098808549 H 4.996354434129 0.553098808549 -4.996354434129 H 0.553098808549 4.996354434129 -4.996354434129 H 6.314679342165 -0.834893029320 0.834893029320 H 6.314679342165 0.834893029320 -0.834893029320 H 6.648496194615 -1.579323701234 -3.281169077705 H 5.286275514187 -3.544673966205 -3.544673966205 H 6.648496194615 -3.281169077705 -1.579323701234 H 3.544673966205 -5.286275514187 -3.544673966205 H 1.579323701234 -6.648496194615 -3.281169077705 H 3.281169077705 -6.648496194615 -1.579323701234 H 3.914663193815 3.914663193815 -6.000626673498 H 2.298208202704 2.298208202704 -6.678028071202 H 3.281169077705 -1.579323701234 -6.648496194615 H 1.579323701234 -3.281169077705 -6.648496194615 H 3.544673966205 -3.544673966205 -5.286275514187 H -2.298208202704 6.678028071202 2.298208202704 H -3.914663193815 6.000626673498 3.914663193815 H -3.914663193815 3.914663193815 6.000626673498 H -2.298208202704 2.298208202704 6.678028071202 H -0.553098808549 4.996354434129 4.996354434129 H -4.996354434129 0.553098808549 4.996354434129 H -4.996354434129 4.996354434129 0.553098808549 H -0.834893029320 0.834893029320 6.314679342165 H 0.834893029320 -0.834893029320 6.314679342165 H -3.281169077705 -1.579323701234 6.648496194615 H -1.579323701234 -3.281169077705 6.648496194615 H -3.544673966205 -3.544673966205 5.286275514187 H -3.544673966205 -5.286275514187 3.544673966205 H -1.579323701234 -6.648496194615 3.281169077705 H -3.281169077705 -6.648496194615 1.579323701234 H -0.834893029320 6.314679342165 0.834893029320 H 0.834893029320 6.314679342165 -0.834893029320 H -3.281169077705 6.648496194615 -1.579323701234 H -3.544673966205 5.286275514187 -3.544673966205 H -1.579323701234 6.648496194615 -3.281169077705 H -0.553098808549 -4.996354434129 -4.996354434129 H -4.996354434129 -4.996354434129 -0.553098808549 H -4.996354434129 -0.553098808549 -4.996354434129 H 0.834893029320 -6.314679342165 0.834893029320 H -0.834893029320 -6.314679342165 -0.834893029320 H -2.298208202704 -6.678028071202 -2.298208202704 H -3.914663193815 -6.000626673498 -3.914663193815 H -3.544673966205 3.544673966205 -5.286275514187 H -3.281169077705 1.579323701234 -6.648496194615 H -1.579323701234 3.281169077705 -6.648496194615 H 0.834893029320 0.834893029320 -6.314679342165 H -0.834893029320 -0.834893029320 -6.314679342165 H -2.298208202704 -2.298208202704 -6.678028071202 H -3.914663193815 -3.914663193815 -6.000626673498 H -6.678028071202 2.298208202704 2.298208202704 H -6.000626673498 3.914663193815 3.914663193815 H -6.648496194615 -1.579323701234 3.281169077705 H -5.286275514187 -3.544673966205 3.544673966205 H -6.648496194615 -3.281169077705 1.579323701234 H -5.286275514187 3.544673966205 -3.544673966205 H -6.648496194615 3.281169077705 -1.579323701234 H -6.648496194615 1.579323701234 -3.281169077705 H -6.314679342165 -0.834893029320 -0.834893029320 H -6.314679342165 0.834893029320 0.834893029320 H -6.000626673498 -3.914663193815 -3.914663193815 H -6.678028071202 -2.298208202704 -2.298208202704 $end
And here are my input file parameters:
$rem MEM_TOTAL 48000 MEM_STATIC 960 JOBTYPE sp EXCHANGE b3lyp BASIS def2-tzvp CIS_N_ROOTS 4 SCF_ALGORITHM diis_gdm CIS_SINGLETS true CIS_TRIPLETS true CALC_SOC true STS_MOM true IQMOL_FCHK true $end
This is the content of the SCF section of the output file:
A restricted SCF calculation will be performed using DIIS, GDM SCF converges when RMS gradient is below 1.0e-08 --------------------------------------- Cycle Energy DIIS error --------------------------------------- 1 -19978.6268538015 4.40e-01 2 -868701.3259110240 1.84e+02 3 -869541.8446004504 1.84e+02 4 -874907.6143515166 1.85e+02 5 -872315.8721118229 1.84e+02 6 -874380.5545428591 1.85e+02 7 -873057.0238735870 1.84e+02 8 -873750.4279140406 1.85e+02 9 -875646.7400514059 1.85e+02 10 -875297.7247332566 1.85e+02 11 -874758.4417308006 1.85e+02 12 -875971.4873713489 1.85e+02 13 -875946.2102140816 1.85e+02 14 -875544.2167887952 1.85e+02 15 -875609.3253957893 1.85e+02 16 -874929.9464730512 1.85e+02 17-5918614.1796252886 7.46e+02 18-8411371.7196255270 6.05e+02 19-9239859.8480598200 5.43e+02 20-8462890.3776093889 5.53e+02 21-9425088.8142104074 5.36e+02 22-9389125.3470191248 5.33e+02 23-9322178.7411765363 5.39e+02 24-9303958.0940554701 5.41e+02 25-9388023.0849448685 5.34e+02 26-9418683.0211817622 5.30e+02 27-11398627.0720297545 3.41e+02 28-12083747.1433884297 2.58e+02 29-12421928.1767782159 1.70e+02 30-12664239.2634986900 6.52e+01 31-12665369.5182279497 1.76e+01 32-12775983.9653341155 1.16e+00 33-12692651.1173310149 2.79e+00 34-12787790.3589690179 3.32e+00 35-12668022.7303298395 3.15e+00 36-12666112.7696821690 3.08e+00 37-12753351.3547777440 1.58e+00 38-12751844.9793572165 1.48e+00 39-12719318.4688073117 5.24e-01 40-12739439.7589352801 7.91e-01 41-12743181.2375025228 1.83e-01 42-12744384.3223299738 1.31e-01 43-12743250.7788753062 8.09e-02 44-12741312.3330480475 1.03e-01 45-12733907.0411213841 3.56e-01 46-12734053.0460137893 3.61e-01 47-12737983.5762829240 2.72e-01 48-12738421.4643373061 2.61e-01 49-12740007.8599114008 2.54e-01 50-12742818.8809344303 2.07e-01 --------------------------------------- Cycle Energy RMS Gradient --------------------------------------- 1-12744205.5375410728 1.01e-01 Descent step 2-12742608.1800612491 1.08e-01 Line search: overstep 3-12744044.9431627262 1.02e-01 Line search: overstep 4-12744189.4697686527 1.01e-01 Line search: overstep 5-12744203.9306781590 1.01e-01 Line search: overstep 6-12744205.3768520672 1.01e-01 Line search: overstep 7-12744205.5214719158 1.01e-01 Line search: overstep 8-12744205.5359343290 1.01e-01 Line search: overstep 9-12744205.5373863392 1.01e-01 Line search: understep 10-12744205.5360760503 1.01e-01 Line search: overstep 11-12744205.5372521952 1.01e-01 Line search: understep 12-12744205.5361998565 1.01e-01 Line search: overstep 13-12744205.5371464584 1.01e-01 Line search: understep 14-12744205.5362927373 1.01e-01 Line search: overstep 15-12744205.5370594729 1.01e-01 Line search: understep 16-12744205.5363764372 1.01e-01 Line search: overstep 17-12744205.5369913429 1.01e-01 Line search: understep GDM:: 16 failed line searches. Resetting 18-12744205.5364361964 1.01e-01 Line search: overstep GDM:: 17 failed line searches. Resetting 19-12744205.5369385742 1.01e-01 Line search: understep GDM:: 18 failed line searches. Resetting 20-12744205.5364850853 1.01e-01 Line search: overstep GDM:: 19 failed line searches. Resetting 21-12744205.5368925780 1.01e-01 Line search: understep GDM:: 20 failed line searches. Resetting 22-12744205.5365233868 1.01e-01 Line search: overstep GDM:: 21 failed line searches. Resetting 23-12744205.5368542839 1.01e-01 Line search: understep GDM:: 22 failed line searches. Resetting 24-12744205.5365555398 1.01e-01 Line search: overstep GDM:: 23 failed line searches. Resetting 25-12744205.5368215945 1.01e-01 Line search: understep GDM:: 24 failed line searches. Resetting 26-12744205.5365804769 1.01e-01 Line search: understep GDM:: 25 failed line searches. Resetting 27-12744205.5365576241 1.01e-01 Line search: overstep GDM:: 26 failed line searches. Resetting 28-12744205.5365797319 1.01e-01 Line search: understep GDM:: 27 failed line searches. Resetting 29-12744205.5365645606 1.01e-01 Line search: overstep GDM:: 28 failed line searches. Resetting 30-12744205.5365754142 1.01e-01 Line search: overstep GDM:: 29 failed line searches. Resetting 31-12744205.5365804341 1.01e-01 Line search: understep GDM:: 30 failed line searches. Resetting 32-12744205.5365759619 1.01e-01 Line search: overstep GDM:: 31 failed line searches. Resetting 33-12744205.5365765132 1.01e-01 Line search: overstep GDM:: 32 failed line searches. Resetting 34-12744205.5365834795 1.01e-01 Line search: understep GDM:: 33 failed line searches. Resetting 35-12744205.5365766622 1.01e-01 Line search: understep GDM:: 34 failed line searches. Resetting 36-12744205.5365773048 1.01e-01 Line search: understep GDM:: 35 failed line searches. Resetting 37-12744205.5365784094 1.01e-01 Line search: understep GDM:: 36 failed line searches. Resetting 38-12744205.5365777556 1.01e-01 Line search: understep GDM:: 37 failed line searches. Resetting 39-12744205.5365779288 1.01e-01 Line search: understep GDM:: 38 failed line searches. Resetting 40-12744205.5365773607 1.01e-01 Line search: understep GDM:: 39 failed line searches. Resetting 41-12744205.5365755595 1.01e-01 Line search: overstep GDM:: 40 failed line searches. Resetting 42-12744205.5365782138 1.01e-01 Line search: understep GDM:: 41 failed line searches. Resetting 43-12744205.5365786180 1.01e-01 Line search: understep GDM:: 42 failed line searches. Resetting 44-12744205.5365768299 1.01e-01 Line search: understep GDM:: 43 failed line searches. Resetting 45-12744205.5365782399 1.01e-01 Line search: understep GDM:: 44 failed line searches. Resetting 46-12744205.5365781412 1.01e-01 Line search: understep GDM:: 45 failed line searches. Resetting 47-12744205.5365748014 1.01e-01 Line search: overstep GDM:: 46 failed line searches. Resetting 48-12744205.5365792867 1.01e-01 Line search: understep GDM:: 47 failed line searches. Resetting 49-12744205.5365831405 1.01e-01 Line search: understep GDM:: 48 failed line searches. Resetting 50-12744205.5365778171 1.01e-01 Line search: understep gen_scfman_exception: SCF failed to converge Q-Chem fatal error occurred in module libgscf/gen_scfman/gen_scfman_main.C, line 218: Error in gen_scfman
I did not encounter any problem with the previous, smaller quantum dots.
Did I do something wrong? How can I resolve this problem?
Thank you for your help !
Best regards!
Iacobellis Nicolas, Ph.D. Student