<div>Dear CP2K developers and users, I am performing linear response NMR calculations using the GAPW method and the CAM-B3LYP functional. I constructed linear regression curves for a set of small organic molecules (benzene, toluene, cyclohexane, hexane, acetone, ethyl acetate, dimethoxyethane, diethyl ether, dioxane, and TMS), comparing PBE and CAM-B3LYP. These regressions were done using both cc-pVQZ and aug-cc-pVQZ basis sets, with and without ADMM. I’ve attached the plots for reference. Surprisingly, CAM-B3LYP slopes are around 1.6 and RMS/MAD errors are significantly higher than PBE. This is unexpected, especially since CAM-B3LYP should in principle provide improved results. Additionally, when testing larger molecules (e.g., see test.xyz, also attached), the computed isotropic shieldings seem unphysical. In some cases, values are much larger than those for TMS carbon atoms or even highly negative, which contradicts expectations. Below is the input file used:</div><div>&FORCE_EVAL METHOD QS &DFT CHARGE 0 MULTIPLICITY 1 BASIS_SET_FILE_NAME /home/sergio/Desktop/pseudopotenciais/BASIS_SET_CP2K POTENTIAL_FILE_NAME /home/sergio/Desktop/pseudopotenciais/PSEUDOTENTIAL_CP2K WFN_RESTART_FILE_NAME NMR-Frame-01_aug-cc-pVQZ-RESTART.wfn &QS METHOD GAPW EPS_DEFAULT 1.0E-18 MIN_PAIR_LIST_RADIUS -1 &END QS &XC &XC_FUNCTIONAL &HYB_GGA_XC_CAM_B3LYP _AC 0.81 _ALPHA 0.65 _BETA -0.46 _OMEGA 0.33 &END HYB_GGA_XC_CAM_B3LYP &END XC_FUNCTIONAL &HF &INTERACTION_POTENTIAL POTENTIAL_TYPE MIX_CL_TRUNC CUTOFF_RADIUS 12 OMEGA 0.33 SCALE_COULOMB 0.19 SCALE_LONGRANGE 0.46 T_C_G_DATA /home/sergio/Desktop/pseudopotenciais/t_c_g.dat &END &SCREENING EPS_SCHWARZ 1.0E-12 &END &MEMORY MAX_MEMORY 1000 EPS_STORAGE_SCALING 0.1 &END MEMORY FRACTION 1.00 &END &END XC &AUXILIARY_DENSITY_MATRIX_METHOD ADMM_TYPE ADMMS &END AUXILIARY_DENSITY_MATRIX_METHOD &SCRF EPS_OUT 4.81 &SPHERE &CENTER ATOM_LIST 1..82 WEIGHT_TYPE UNIT &END CENTER RADIUS 10.8 &END SPHERE &END SCRF &MGRID CUTOFF 600 REL_CUTOFF 60 &END MGRID &SCF EPS_SCF 1.0E-6 MAX_SCF 20 SCF_GUESS RESTART &OT T MINIMIZER DIIS PRECONDITIONER FULL_ALL LINESEARCH 3PNT &END OT &OUTER_SCF T EPS_SCF 1E-06 MAX_SCF 20 &END OUTER_SCF &END SCF &END DFT &SUBSYS &CELL ! box size ABC [angstrom] 25.00000 25.00000 25.00000 &END CELL &TOPOLOGY COORD_FILE_NAME test.xyz COORD_FILE_FORMAT XYZ &END TOPOLOGY &KIND O LEBEDEV_GRID 120 RADIAL_GRID 250 BASIS_SET ORB aug-cc-pVQZ BASIS_SET AUX_FIT admm-3 POTENTIAL ALL &END KIND &KIND C LEBEDEV_GRID 120 RADIAL_GRID 250 BASIS_SET ORB aug-cc-pVQZ BASIS_SET AUX_FIT admm-3 POTENTIAL ALL &END KIND &KIND H LEBEDEV_GRID 120 RADIAL_GRID 250 BASIS_SET ORB aug-cc-pVQZ BASIS_SET AUX_FIT admm-3 POTENTIAL ALL &END KIND &END SUBSYS &PROPERTIES &LINRES &LOCALIZE &END LOCALIZE PRECONDITIONER FULL_ALL MAX_ITER 2000 &CURRENT GAUGE ATOM ORBITAL_CENTER ATOM &END CURRENT &NMR INTERPOLATE_SHIFT T &PRINT &CHI_TENSOR &END CHI_TENSOR &END PRINT &END NMR &END LINRES &END PROPERTIES &END FORCE_EVAL &GLOBAL PRINT_LEVEL MEDIUM !(or SILENT/LOW/HIGH/…) PROJECT_NAME NMR-Frame-01_aug-cc-pVQZ RUN_TYPE LINEAR_RESPONSE WALLTIME 10000000000 &END GLOBAL</div><div> </div><div> I'd appreciate any suggestions or insights into these points. Looking forward to any advice.</div><div> </div><div>Best regards,</div><div>Sergio Tavares</div> -- You received this message because you are subscribed to the Google Groups "cp2k" group. To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k+unsubscribe@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>. To view this discussion visit <a href="https://groups.google.com/d/msgid/cp2k/b19bf001-7dd6-422d-b699-a8d4e94bb842n%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/b19bf001-7dd6-422d-b699-a8d4e94bb842n%40googlegroups.com</a>.