<div dir="ltr">Hello, I wanted to calculate the atomic energy of oxygen. I used the CP2K tutorial for GEO_OPT of H2O as an example to generate the input file. What I noticed is that the energy calculation for atomic did not converge after 500 SCF steps if I did not use smearing. Would anyone be able to explain why this is? Because I thought for such a small atom smearing would not be necessary. The energy for atomic oxygen also converged when I used the OT method but I thought it best to use diagonalization to keep consistent with the input I use for calculations on my metal systems. This is what I believe is the relevant part of the input form the calculation that converged. I indicated which lines were omitted from the calculation that did not coverge: &FORCE_EVAL METHOD QS &DFT BASIS_SET_FILE_NAME BASIS_MOLOPT POTENTIAL_FILE_NAME GTH_POTENTIALS &MGRID CUTOFF 400 REL_CUTOFF 60 NGRIDS 4 &END MGRID &QS EPS_DEFAULT 1.0E-14 MAP_CONSISTENT &END QS &SCF SCF_GUESS ATOMIC EPS_SCF 1.0E-7 MAX_SCF 500 ADDED_MOS 200 Added MOS was omitted in the calculation that did not converge. CHOLESKY INVERSE &SMEAR ON METHOD FERMI_DIRAC ELECTRONIC_TEMPERATURE [K] 700 This smear section was omitted in the calculation that did not converge. &END SMEAR &DIAGONALIZATION ALGORITHM STANDARD &END DIAGONALIZATION &MIXING METHOD BROYDEN_MIXING ALPHA 0.1 BETA 1.5 NBROYDEN 8 &END MIXING &END SCF &XC &XC_FUNCTIONAL PBE &PBE PARAMETRIZATION REVPBE &END PBE &END XC_FUNCTIONAL &VDW_POTENTIAL DISPERSION_FUNCTIONAL PAIR_POTENTIAL &PAIR_POTENTIAL TYPE DFTD3 REFERENCE_FUNCTIONAL PBE CALCULATE_C9_TERM .TRUE. PARAMETER_FILE_NAME dftd3.dat R_CUTOFF 15.0 VERBOSE_OUTPUT .TRUE. &END PAIR_POTENTIAL &END vdw_POTENTIAL &END XC UKS .TRUE. MULTIPLICITY 3 Any help with this would be appreciated. Thanks </div>