Hi All<div><br></div><div>I tried to optimize a O2 molecule (triplet) when MULTIPLICITY=1 or 3, respectively. And the result is that their energies were equal. </div><div>So I used their wfn file to calculate the energy finely. But an error occurred when I used the wfn file whose MULTIPLICITY=3. </div><div> *******************************************************************************<br> *   ___                                                                       *<br> *  /   \                                                                      *<br> * [ABORT]                                                                     *<br> *  \___/      Restarting an LSD calculation from an LDA wfn only works for    *<br> *    |                         multiplicity=1 (singlets).                     *<br> *  O/|                                                                        *<br> * /| |                                                                        *<br> * / \                                                          qs_mo_io.F:934 *<br> *******************************************************************************<br></div><div><br></div><div>Then I closed the SCF_GUASS RESTART,  the calculation completed successfully. </div><div>and the energy of MULTIPLICITY=3 was really lower than MULTIPLICITY=1.</div><div><br></div><div>So I want to confirm if the MULTIPLICITY setting doesn’t work in GEO_OPT?</div><div><br></div><div><br></div><div><br></div><div><br></div>