<div dir="ltr">Hello, I've been running CI-NEB calculations on CO2 dissociation on 55-atom NPs. I was able to get a converged NEB but the resulting barrier for dissociation was very small ~0.05 eV. I am a bit unsure about this result considering the TS energies I've come across for CO2 dissociation on transition metals are ~0.2 - 1 eV. My initial and final states were optimized using SCF 1E-8 and forces 4E-5. When the NEB completed I found one single imaginary frequency, which appears to correspond to CO - O dissociation. I was wondering if anyone has come across the issue where only small barriers were detected but not expected? I've included the CI-NEB section in below. I've also attached my whole NEB input file and output and the resulting energy file and input file and molden file for the transition state. &MOTION &BAND NPROC_REP 20 BAND_TYPE CI-NEB NUMBER_OF_REPLICA 8 K_SPRING 0.01 &OPTIMIZE_BAND OPT_TYPE DIIS OPTIMIZE_END_POINTS .FALSE. &DIIS MAX_STEPS 1000 N_DIIS 7 &END &END &REPLICA COORD_FILE_NAME 1.xyz &END REPLICA &REPLICA COORD_FILE_NAME 2.xyz &END REPLICA &REPLICA COORD_FILE_NAME 3.xyz &END REPLICA &REPLICA COORD_FILE_NAME 4.xyz &END REPLICA &REPLICA COORD_FILE_NAME 5.xyz &END REPLICA &REPLICA COORD_FILE_NAME 6.xyz &END REPLICA &REPLICA COORD_FILE_NAME 7.xyz &END REPLICA &REPLICA COORD_FILE_NAME 8.xyz &END REPLICA ALIGN_FRAMES .FALSE. ROTATE_FRAMES .FALSE. &CONVERGENCE_CONTROL MAX_DR 0.002 MAX_FORCE 0.002 RMS_DR 0.001 RMS_FORCE 0.001 &END CONVERGENCE_CONTROL Thanks, Natalie </div>