<div dir="ltr">Dear forum I'm trying to perform a QM/MM steered molecular dynamic simulation. the initial pdb has Na and Cl atoms and firstly I get this error. <br><br><div> *******************************************************************************</div><div> *   ___                                                                       *</div><div> *  /   \                                                                      *</div><div> * [ABORT]       Unknown element for KIND <NA+>. This problem can be fixed     *</div><div> *  \___/  specifying properly elements in PDB or specifying a KIND section or *</div><div> *    |                getting in touch with one of  the developers!           *</div><div> *  O/|                                                                        *</div><div> * /| |                                                                        *</div><div> * / \                                                    topology_util.F:1271 *</div><div> *******************************************************************************</div><div><br></div><div>the I add the Na and Cl element in atom filed ( column 77-78) <br>but I still has the error message. </div><div><br></div><div>Then I add this lines to input file </div><div><br><div>    &KIND NA+</div><div>     ELEMENT Na</div><div>    &END KIND</div><div>    &KIND Cl-</div><div>     ELEMENT Cl</div><div>    &END KIND</div><div><br></div><div>and calculation runs but I get </div><br><div><br></div><div> *******************************************************************************</div><div> *   ___                                                                       *</div><div> *  /   \                                                                      *</div><div> * [ABORT]                                                                     *</div><div> *  \___/                             CPASSERT failed                          *</div><div> *    |                                                                        *</div><div> *  O/|                                                                        *</div><div> * /| |                                                                        *</div><div> * / \                                                         qmmm_init.F:797 *</div><div> *******************************************************************************</div><div><br></div><div><br></div><div> ===== Routine Calling Stack =====</div><div><br></div><div>            2 qmmm_env_create</div><div>            1 CP2K</div><div><br></div><div><br></div><div>After trying different preconditioners and values EPS_DEFAULT values as suggested in <a href="https://www.cp2k.org/faq:cholesky_decomp_failed">https://www.cp2k.org/faq:cholesky_decomp_failed</a> </div><div><br></div><div>I still get this message, so I think that there is an error in the initial PDB . </div><div><br></div><div>Do you have any recommendations? </div><div><br></div><div>Thank you for your time and consideration. </div><div>David.</div><br><br><br></div></div>