<html><head></head><body><div style="color:#000; background-color:#fff; font-family:verdana, helvetica, sans-serif;font-size:13px"><div id="yui_3_16_0_1_1474387740114_3170">Dear Molpro users,</div><div id="yui_3_16_0_1_1474387740114_3171"> </div><div id="yui_3_16_0_1_1474387740114_3172">I’m running an excited-state geometry optimization of a singlet diradical molecule,</div><div id="yui_3_16_0_1_1474387740114_3173">using state-average CASSCF.</div><div id="yui_3_16_0_1_1474387740114_3184"><br id="yui_3_16_0_1_1474387740114_3185"></div><div id="yui_3_16_0_1_1474387740114_3186">The OPT ran about ten iterations and the values of DE, GRAD and STEP become closer to the threshold. </div><div id="yui_3_16_0_1_1474387740114_3187">And the structure maintains almost symmetric in the progress.</div><div id="yui_3_16_0_1_1474387740114_3188"><br id="yui_3_16_0_1_1474387740114_3189"></div><div id="yui_3_16_0_1_1474387740114_3190">However, I found the following message after 10 steps optimization:</div><div id="yui_3_16_0_1_1474387740114_3191"> no convergence in dis1, ss= 0.324350611092190</div><div id="yui_3_16_0_1_1474387740114_3192"> no convergence in dis1, ss= 0.226045759634780</div><div id="yui_3_16_0_1_1474387740114_3193"><br id="yui_3_16_0_1_1474387740114_3194"></div><div id="yui_3_16_0_1_1474387740114_3195">The iteration close to this step has quite larger DE, GRAD and STEP values, which is like re-calculate optimization from the beginning.</div><div id="yui_3_16_0_1_1474387740114_3196"><br></div><div id="yui_3_16_0_1_1474387740114_3196">Most importantly, the structure change to asymmetric conformation – one ring maintains phenyl ring and another is like the chemical structure of cyclohexa-1,4-diene (it is like.. without aromaticity).</div><div id="yui_3_16_0_1_1474387740114_3196">(The input structure is symmetric with one phenyl ring on the right and one phenyl ring on the left. </div><div id="yui_3_16_0_1_1474387740114_3389">It has Cs symmetry but the setting in input file is “nosym”.)</div><div id="yui_3_16_0_1_1474387740114_3205"><br id="yui_3_16_0_1_1474387740114_3206"></div><div id="yui_3_16_0_1_1474387740114_3205"><br></div><div id="yui_3_16_0_1_1474387740114_3207">Does anyone know what "no convergence in dis1" means?</div><div id="yui_3_16_0_1_1474387740114_3208">Any comments about this message are always welcome.</div><div id="yui_3_16_0_1_1474387740114_3209"> </div><div id="yui_3_16_0_1_1474387740114_3210">Thank you!</div><div id="yui_3_16_0_1_1474387740114_3213"><br id="yui_3_16_0_1_1474387740114_3214"></div><div id="yui_3_16_0_1_1474387740114_3215"><br id="yui_3_16_0_1_1474387740114_3216"></div><div id="yui_3_16_0_1_1474387740114_3217">Sincerely,</div><div id="yui_3_16_0_1_1474387740114_3218"> </div><div dir="ltr" id="yui_3_16_0_1_1474387740114_3219">Cherry, Chun-Jui Tan</div><div class="signature" id="yui_3_16_0_1_1474387740114_3040"><div></div></div></div></body></html>