<div dir="ltr">Dear Marcella,<div><br></div><div>thank you for you reply!</div><div><br></div><div>"The combination of functional, DFT+U, basis-sets and potentials might not be optimal.</div><div>According to our last experience with CeO2, to get a good description of the electronic structure we needed a small core Ce element, with 30 valence electrons. "</div><div><br></div><div>Does CP2K provide other basis set and small core potential ? I don't think so, do you create potential and basis set yourself? </div><div>This system is Gold supported CeO2 cluster, the band gap of this whole system is pretty small, so I don't know if it is necessary to add U value.</div><div><br></div><div><div>"Have you already tried the following things?</div><div>- reduce the mixing coefficient alpha</div><div>- increase the smearing temperature</div><div>- use a different extrapolation method, e.g., prev_wf</div><div>- tighten the eps_default"</div></div><div><br></div><div>I try to increase and reduce mixing value of alpha, it doesn't help, also try to increase smearing temperature, and many other keywords. </div><div>I didn't try other extrapolation method, I will try it.</div><div>At beginning the EPS_SCF is 1.0E-6, I just loose it when SCF does't converge. For MD simulation, the geometries diverge too much, this is main reason that SCF doesn't converge. I hope there is something can improve it.</div><div><br></div><div>All the best,</div><div>Yong</div><div><br></div><div><div><br></div></div><div><br></div><div>On Tuesday, March 29, 2016 at 9:41:54 PM UTC+8, Marcella Iannuzzi wrote:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;"><div dir="ltr">Dear Yong Li,<div><br></div><div>your system is not the easiest to treat with DFT. </div><div>I am not too much surprised that you encounter convergence problems. </div><div>The combination of functional, DFT+U, basis-sets and potentials might not be optimal.</div><div>According to our last experience with CeO2, to get a good description of the electronic structure we needed a small core Ce element, with 30 valence electrons. </div><div><br></div><div>Have you already tried the following things?</div><div>- reduce the mixing coefficient alpha</div><div>- increase the smearing temperature</div><div>- use a different extrapolation method, e.g., prev_wf</div><div>- tighten the eps_default</div><div><br></div><div>Kind regards</div><div>Marcella</div><div><br></div><div><div><br>On Saturday, March 26, 2016 at 6:40:18 PM UTC+1, Yong Li wrote:<blockquote class="gmail_quote" style="margin:0;margin-left:0.8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><font size="4">Dear Sir/Madam,</font><div><font size="4"><br></font></div><div><font size="4">I was running a large AIMD simulation (about 5200 basis functions) for Au surface supported CeO</font><font size="1">2</font><font size="4"> cluster ( (Au(111) surface has</font><span style="font-size:large">180 Au atoms</span><font size="4">, and Ce</font><font size="1">10</font><font size="4">O</font><font size="1">20</font><font size="4"> cluster). </font></div><div><font size="4"><br></font></div><div><font size="4">At the beginning, simulation goes well, then it has a very serious convergence problems at around step number of 350. it can't get converged no matter what I do to the SCF control. </font></div><div><font size="4"><br></font></div><div><font size="4">Even if I make it converged coincidentally, but it will not converge after considering Kinetic energy and temperature.</font></div><div><font size="4"><br></font></div><div><font size="4">I tried every method I can find， but I can‘t figure it out.</font></div><div><font size="4"><br></font></div><div><font size="4">I am depressed and frustrated now, hope someone could help me out with it. Any suggestions are appreciated!!</font></div><div><font size="4"><br></font></div><div><font size="4">The input output file were enclosed in attachment, part of input file is as follows</font></div><div><font size="4"><br></font></div><div><font size="4"><div> </div><div><br></div><div> MULTIPLICITY 1</div><div> PLUS_U_METHOD MULLIKEN_CHARGES</div><div> &SCF</div><div> MAX_SCF 100</div><div> EPS_SCF 7.0E-05</div><div> CHOLESKY INVERSE</div><div> SCF_GUESS ATOMIC</div><div> ADDED_MOS 400</div><div> &DIAGONALIZATION T</div><div> ALGORITHM STANDARD</div><div> &END DIAGONALIZATION</div><div> &OUTER_SCF T</div><div> EPS_SCF 8.0000000000000001E-05</div><div> MAX_SCF 5</div><div> &END OUTER_SCF</div><div> &SMEAR T</div><div> # METHOD ENERGY_WINDOW</div><div> METHOD FERMI_DIRAC</div><div> ELECTRONIC_TEMPERATURE 3.0000000000000000E+02</div><div> &END SMEAR</div><div> &MIXING T</div><div> METHOD BROYDEN_MIXING</div><div> ALPHA 0.1</div><div> BETA 1.5</div><div> NBUFFER 8</div><div> &END MIXING</div><div> &PRINT</div><div> &RESTART SILENT</div><div> FILENAME =RESTART.wfn</div><div> &EACH</div><div> MD 5</div><div> &END EACH</div><div> &END RESTART</div><div> &END PRINT</div><div> &END SCF</div><div> &QS</div><div> EPS_DEFAULT 1.0000000000000000E-11</div><div> EPS_PGF_ORB 1.0000000000000001E-05</div><div> EXTRAPOLATION ASPC</div><div> EXTRAPOLATION_ORDER 3</div><div> &END QS</div><div> &MGRID</div><div> CUTOFF 5.0000000000000000E+02</div><div> &END MGRID</div><div> &XC</div><div> DENSITY_CUTOFF 1.0000000000000000E-10</div><div> GRADIENT_CUTOFF 1.0000000000000000E-10</div><div> TAU_CUTOFF 1.0000000000000000E-10</div><div> &XC_GRID</div><div> XC_SMOOTH_RHO NN10</div><div> XC_DERIV SPLINE2_SMOOTH</div><div> &END XC_GRID</div><div> &XC_FUNCTIONAL NO_SHORTCUT</div><div> &PBE T</div><div> &END PBE</div><div> &END XC_FUNCTIONAL</div><div> &END XC</div><div> &PRINT</div><div> &MULLIKEN SILENT</div><div> FILENAME =md.mulliken</div><div> &EACH</div><div> MD 5</div><div> &END EACH</div><div> &END MULLIKEN</div><div> &END PRINT</div><div> &END DFT</div><div> &SUBSYS</div></font></div><div><font size="4"><br></font></div><div><font size="4"><br></font></div><div><font size="4"><br></font></div><div><font size="4"><br></font></div></div></blockquote></div></div></div></blockquote></div></div>