<div dir="ltr">Dear all CP2K users, I am trying to optimize a Graphene Quantum Dot using BLYP-DFT-D3/DZVP method as implemented in CP2K. While optimizing I have observed that, SCF energy is decreasing (i.e. becoming more negative) at the beginning of the run, but after few outer-SCF loops, the energy starts increasing and the increment is going on and on if I am leaving the system to run. Also, I have observed that the inner-SCF energy has reached a convergence (for this system) value of ~ 10^(-5) after 2 outer-SCF cycles (where my EPS_SCF is 1.0E-6) and after the beginning of the 3rd outer-SCF tolerance has increased to a value of ~ 10^(-3). I would like to get your suggestions on any way to avoid this convergence issue. The input file and the output file (just before and after the 2nd outer-SCF) are given below (hopping they may be help you in suggesting). Thank you all, Sincerely, Sharma. P.S: I have checked in the mailing list but I couldn't exactly found any post on this issue (though there are on BOMD-energy increment etc.) <div style="text-align: center;">Input_file: </div> &FORCE_EVAL METHOD Quickstep &DFT CHARGE = 0 MULTIPLICITY = 2 LSD # for odd number of electrons and specifying this keyword itself enforces for spin-polarized calculations BASIS_SET_FILE_NAME BASIS_MOLOPT POTENTIAL_FILE_NAME GTH_POTENTIALS &MGRID CUTOFF 320 NGRIDS 5 REL_CUTOFF 40 &END MGRID &QS METHOD GPW EPS_DEFAULT 1.0E-10 &END QS &SCF SCF_GUESS RESTART EPS_SCF 1.0E-6 MAX_SCF 100 &OUTER_SCF EPS_SCF 1.0E-6 MAX_SCF 500 &END &OT MINIMIZER CG PRECONDITIONER FULL_ALL ENERGY_GAP 0.001 STEPSIZE 0.05 &END &END SCF &XC &XC_FUNCTIONAL BLYP &END XC_FUNCTIONAL &XC_GRID XC_DERIV SPLINE2 XC_SMOOTH_RHO NN50 &END XC_GRID &vdW_POTENTIAL DISPERSION_FUNCTIONAL PAIR_POTENTIAL # POTENTIAL_TYPE is alias to DISPERSION_FUNCTIONAL &PAIR_POTENTIAL TYPE DFTD3 PARAMETER_FILE_NAME dftd3.dat REFERENCE_FUNCTIONAL BLYP &END PAIR_POTENTIAL &END vdW_POTENTIAL &END XC &POISSON POISSON_SOLVER WAVELET PERIODIC NONE &END POISSON &END DFT &SUBSYS &CELL ABC 38.0 38.0 38.0 ALPHA_BETA_GAMMA 90.0 90.0 90.00 PERIODIC NONE &END CELL &TOPOLOGY &CENTER_COORDINATES &END &END &COORD @INCLUDE gqd_270.xyz &END COORD &KIND H BASIS_SET DZVP-MOLOPT-SR-GTH POTENTIAL GTH-BLYP-q1 &END KIND &KIND C BASIS_SET DZVP-MOLOPT-SR-GTH POTENTIAL GTH-BLYP-q4 &END KIND &KIND N BASIS_SET DZVP-MOLOPT-SR-GTH POTENTIAL GTH-BLYP-q5 &END KIND &END SUBSYS &END FORCE_EVAL &GLOBAL PROJECT au20_tetra_on_n-gqd RUN_TYPE GEO_OPT PRINT_LEVEL MEDIUM &END GLOBAL &MOTION &GEO_OPT OPTIMIZER BFGS MAX_ITER 5000 MAX_FORCE 1.00D-4 TYPE MINIMIZATION &END &END MOTION ########################################################################################################################### <div style="text-align: center;">OUTPUT-FILE:</div> 98 OT LS 0.54E-01 6.9 -1982.8376246687 Trace(PS): 1174.9999638412 Electronic density on regular grids: -1174.9999638398 0.0000361602 Core density on regular grids: 1174.9999998887 -0.0000001113 Total charge density on r-space grids: 0.0000360489 Total charge density g-space grids: 0.0000360489 99 OT CG 0.54E-01 12.3 0.00000845 -1982.8383595833 -7.61E-05 Trace(PS): 1174.9999635922 Electronic density on regular grids: -1174.9999635907 0.0000364093 Core density on regular grids: 1174.9999998887 -0.0000001113 Total charge density on r-space grids: 0.0000362980 Total charge density g-space grids: 0.0000362980 100 OT LS 0.22E+00 6.9 -1982.8383813757 *** SCF run NOT converged *** Electronic density on regular grids: -1174.9999635907 0.0000364093 Core density on regular grids: 1174.9999998887 -0.0000001113 Total charge density on r-space grids: 0.0000362980 Total charge density g-space grids: 0.0000362980 Overlap energy of the core charge distribution: 0.00005046108667 Self energy of the core charge distribution: -4271.91259980407449 Core Hamiltonian energy: 1351.88408937624945 Hartree energy: 1448.17384258600623 Exchange-correlation energy: -510.06161737575133 Dispersion energy: -0.92214661917833 Total energy: -1982.83838137566136 outer SCF iter = 3 RMS gradient = 0.84E-05 energy = -1982.8383813757 ----------------------------------- OT --------------------------------------- Allowing for rotations: F Optimizing orbital energies: F Minimizer : CG : conjugate gradient Preconditioner : FULL_ALL : diagonalization, state selective Precond_solver : DEFAULT Line search : 2PNT : 2 energies, one gradient stepsize : 0.05000000 energy_gap : 0.00100000 eps_taylor : 0.10000E-15 max_taylor : 4 mixed_precision : F ----------------------------------- OT --------------------------------------- Step Update method Time Convergence Total energy Change ------------------------------------------------------------------------------ Trace(PS): 1174.9999628452 Electronic density on regular grids: -1174.9999628438 0.0000371562 Core density on regular grids: 1174.9999998887 -0.0000001113 Total charge density on r-space grids: 0.0000370449 Total charge density g-space grids: 0.0000370449 1 OT CG 0.50E-01 24.7 0.00073898 -1982.8383578477 1.74E-06 Trace(PS): 1174.6089204778 Electronic density on regular grids: -1174.6089204763 0.3910795237 Core density on regular grids: 1174.9999998887 -0.0000001113 Total charge density on r-space grids: 0.3910794124 Total charge density g-space grids: 0.3910794124 2 OT LS 0.16E-01 6.8 -1982.7669389193 Trace(PS): 1174.8781005916 Electronic density on regular grids: -1174.8781005901 0.1218994099 Core density on regular grids: 1174.9999998887 -0.0000001113 Total charge density on r-space grids: 0.1218992986 Total charge density g-space grids: 0.1218992986 3 OT CG 0.16E-01 12.3 0.00075231 -1982.7595972134 7.88E-02 </div>