<div dir="ltr">Hi all,<div><br></div><div><br></div><div><div><br></div><div>I am observing some strange behavior during a NEB calculation. Basically, the job has been running for a long time, but didn't seem to get close to converging. Checking the output it turns out that following step 20 (so right at the beginning)</div></div><div>there weren't any convergence checks any more. Hence, this is the last convergence check I get:</div><div><br></div><div><br></div><div><div> *******************************************************************************</div><div> BAND TYPE           =                      CI-NEB</div><div> BAND TYPE OPTIMIZATION     =                        SD</div><div> STEP NUMBER          =                        20</div><div> NUMBER OF NEB REPLICA     =                        16</div><div> DISTANCES REP =     0.904376     0.970665     1.003149     0.989286</div><div>            0.919178     0.879384     0.898267     0.929957</div><div>            0.917761     0.958179     0.913835     0.867431</div><div>            0.835008     0.833033     0.824020</div><div> ENERGIES [au] =   -4477.534580   -4477.534142   -4477.532777   -4477.530610</div><div>          -4477.527827   -4477.524573   -4477.520887   -4477.517698</div><div>          -4477.523689   -4477.538783   -4477.543540   -4477.546473</div><div>          -4477.548883   -4477.550356   -4477.551290   -4477.540294</div><div> BAND TOTAL ENERGY [au]     =              -71640.56568602792686</div><div> *******************************************************************************</div><div> *******************************************************************************</div><div> RMS DISPLACEMENT =  0.00015   [ 0.00010]                ( NO)</div><div> MAX DISPLACEMENT =  0.00872   [ 0.00020]                ( NO)</div><div> RMS FORCE     =  0.00014   [ 0.00030]                (YES)</div><div> MAX FORCE     =  0.00652   [ 0.00080]                ( NO)</div><div> *******************************************************************************</div><div><br></div><div> NEB| Computing Energies and Forces</div><div> NEB| REPLICA Nr.   1- Energy and Forces</div><div> NEB|                   Total Energy:      -4477.534579955</div><div> NEB|   ATOM               X         Y         Z</div><div> NEB|    Rh            0.000001025   -0.000015044    0.000003010</div><div> NEB|    P            -0.000001915    0.000000815   -0.000002622</div><div> NEB|    C            -0.000000579    0.000005799    0.000000635</div><div> NEB|    C            -0.000003518   -0.000003207   -0.000002095</div></div><div><br></div><div><br></div><div>What follows are Energies and Forces for the rest of the file. I can't find any problems with SCF convergence in the BAND files, the energy profile looks perfectly sensible, the trajectory of the last 16 images also makes total sense to me. I find it hard to believe that this is a program bug, since the very same input has successfully worked for a good number of transition states in the meantime, on the very same system. However, it strikes me that there appear no convergence reports after 20 steps. I also noted that there isn't necessarily such a </div><div>convergence check after forces have been calculated for the 16 images I have defined, so how does this work exactly? And why did I still get sensible results for the other Transition States, while in the present example the calculation seems to run into nowhere.</div><div><br></div><div>Thanks for your comments, your help is much appreciated. </div><div><br></div><div><br></div><div>Tobias</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div></div>