<div style="line-height:1.7;color:#000000;font-size:14px;font-family:arial"><div>Dear Molpro community,</div><div>    Using the CASSCF method, I calculated the frequencies of a molecule under the C1 geometries. However, one imaginary frequency (70.9i) are found. </div><div>    My main input file is below:</div><div>***,<br>  memory,400,M                                                                                                                                                 </div><div>  geomtyp=xyz<br>  symmetry,nosym<br>  geometry={<br>  16</div><div>  <br>   input.xyz</div><div>  }<br>  <br>   basis=6-31G*<br>   gprint,civector<br>  <br>   {rhf<br>   occ,   46;<br>   closed,46;<br>   wf,92,1,0;<br>   orbital,2100.2;}<br>  <br>   {multi<br>   occ,   50;<br>   closed,42;<br>   orbital,2140.2;<br>   wf,92,1,0;state,1;}<br>  <br>   optg<br>   frequencies<br>   put,gaussian,cas88_optc1_s0.gjf;<br>   put,molden,cas88_optc1_s0.molden;<br>  ---</div><div> </div><div>How I can solve the problem £¿</div><div>Thanks in advance,</div><div>xgguo <br></div><div><div><div><br> </div></div></div></div><br><br><span title="neteasefooter"><span id="netease_mail_footer"></span></span>