<div dir="ltr">Dear All,<div> </div><div>I am pretty new to CP2K and still learning the basics of the program. I want to get the energy of the energy of the reaction: Fe(g) + S(g) -> FeS(g). To begin with, I simply did single point calculation of iron atom using Gaussian03 and CP2K. Browsing through the previous posts, I figured out that the ECP basis sets used by most quantum chemists cannot be used in CP2K. Even if I use different level of theory and basis sets across the two programs, I would anticipate roughly similar energies if not exactly same. I used basis set B3LYP/SDD in Gaussian03 and SZV-MOLOPT-SR-GTH in CP2K. The energies I get from Gaussian is: -123.85372 while in CP2K: -19.96605887771384. Even if the two programs results in two spin states I would not expect such large different. </div><div> </div><div>I do not know what I am doing wrong. Any help will be greatly appreciated. I have included the input below. Apart from these, I have few more general questions:</div><div> </div><div>(a) Is there any recommended combination of pseudopotential and basis set for complex compounds containing metal iron. There are also: carbon, oxygen, sulfur, and nitrogen in the system.</div><div> </div><div>(b) Should I use GPW or do all electron calculation using GAPW. I would have used ECP basis set, if I had to use Gaussian03. But I am not sure what is right way proceed with CP2K.</div><div> </div><div>(c) Any suggestion for the functional available in CP2K for studying iron complexes of high spin multiplicity. </div><div> </div><div>(d) I saw ECP_POTENTIALS file on CP2K Github, is it possible to use ECPs like SDD, LANL2DZ, etc. in CP2K.</div><div> </div><div> </div><div>Here is my CP2K input:</div><div> &GLOBAL PROJECT Fe RUN_TYPE ENERGY PRINT_LEVEL MEDIUM WALLTIME 86400 &END GLOBAL &FORCE_EVAL METHOD Quickstep &DFT BASIS_SET_FILE_NAME /share/apps/cp2k/cp2k/tests/QS/BASIS_MOLOPT POTENTIAL_FILE_NAME /share/apps/cp2k/cp2k/tests/QS/GTH_POTENTIALS CHARGE 0 MULTIPLICITY 5 UKS T &MGRID CUTOFF 400 REL_CUTOFF 60 &END MGRID &QS METHOD GPW EPS_DEFAULT 1.0E-12 &END QS &SCF MAX_SCF 500 &OUTER_SCF EPS_SCF 1.0E-6 MAX_SCF 60 &END OUTER_SCF &END SCF &POISSON PERIODIC NONE PSOLVER WAVELET &END POISSON &XC &XC_FUNCTIONAL PADE &END XC_FUNCTIONAL &END XC &END DFT &SUBSYS &CELL ABC 7.00 7.00 7.00 PERIODIC NONE &END CELL &COORD Fe 0.0000 0.0000 0.0000 &END COORD &KIND Fe BASIS_SET SZV-MOLOPT-SR-GTH POTENTIAL GTH-PADE-q8 &END KIND &END SUBSYS &END FORCE_EVAL Thanks,Megha</div><div> </div><div> </div> </div>