<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1423238354914_2949" dir="ltr"><span id="yui_3_16_0_1_1423238354914_3124">Is there any possible sign in case of symmetry breaking that could make me aware of the fact </span></div><div id="yui_3_16_0_1_1423238354914_2949" dir="ltr"><span id="yui_3_16_0_1_1423238354914_4607">that my targeted spin state is contaminated </span>by higher spin multiplicities in <b id="yui_3_16_0_1_1423238354914_4578">contracted</b> mrci ?</div><div id="yui_3_16_0_1_1423238354914_2949" dir="ltr"><span><br></span></div><div id="yui_3_16_0_1_1423238354914_2949" dir="ltr"><span id="yui_3_16_0_1_1423238354914_4580">If no, how can i run mrci in molpro without contraction to be able to compare the results of both methods ?</span></div><div id="yui_3_16_0_1_1423238354914_2949" dir="ltr"><span><br></span></div><div id="yui_3_16_0_1_1423238354914_2949" dir="ltr">Martin</div> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"> <font size="2" face="Arial"> Peter Knowles <KnowlesPJ@cardiff.ac.uk> schrieb am 8:29 Freitag, 6.Februar 2015:<br> </font> </div> <br><br> <div class="y_msg_container">In the MRCI method, the energies are obtained from a linear eigenvalue problem. Thus provided that the hamiltonian matrix is a representation from a basis that is closed under symmetry operations (spin or space), its eigenfunctions will be symmetry pure. In the contracted MRCI method, it is sometimes possible to arrange for this not to be true, but normally, with a reference wavefunction that is a definite symmetry, you should not expect symmetry breaking.<br clear="none"><br clear="none">Peter<br clear="none"><div class="yqt1136817877" id="yqtfd82075"><br clear="none">> On 5 Feb 2015, at 19:03, Martin Spenke <<a shape="rect" ymailto="mailto:martinspenke@yahoo.de" href="mailto:martinspenke@yahoo.de">martinspenke@yahoo.de</a>> wrote:<br clear="none">> <br clear="none">> Dear all, <br clear="none">> <br clear="none">> is the mrci calculation in molpro purified from contributions of higher spin multiplicities<br clear="none">> when computing excitation energy of a singlet spin state ?<br clear="none">> <br clear="none">> Bests<br clear="none">> Martin</div><br clear="none">> _______________________________________________<br clear="none">> Molpro-user mailing list<br clear="none">> <a shape="rect" ymailto="mailto:Molpro-user@molpro.net" href="mailto:Molpro-user@molpro.net">Molpro-user@molpro.net</a><br clear="none">> <a shape="rect" href="http://www.molpro.net/mailman/listinfo/molpro-user" target="_blank">http://www.molpro.net/mailman/listinfo/molpro-user</a><br clear="none"><br clear="none">--<br clear="none">Prof. Peter J. Knowles <br clear="none">School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK<br clear="none">Telephone: +44 29 208 79182<br clear="none">Email: <a shape="rect" ymailto="mailto:KnowlesPJ@Cardiff.ac.uk" href="mailto:KnowlesPJ@Cardiff.ac.uk">KnowlesPJ@Cardiff.ac.uk</a> <br clear="none"><br clear="none">Yr Athro Peter J. Knowles<br clear="none">Yr Ysgol Cemeg, Prifysgol Caerdydd,<br clear="none">Prif Adeilad, Plas y Parc<br clear="none">Caerdydd CF10 3AT, DU<br clear="none">Ffôn: +44 2920 879182<br clear="none">Ebost: <a shape="rect" ymailto="mailto:KnowlesPJ@Caerdydd.ac.uk" href="mailto:KnowlesPJ@Caerdydd.ac.uk">KnowlesPJ@Caerdydd.ac.uk</a><br clear="none">Ysgrifennwch ataf yn Gymraeg neu Saesneg<div class="yqt1136817877" id="yqtfd81536"><br clear="none"><br clear="none"><br clear="none"><br clear="none"><br clear="none"><br clear="none"><br clear="none"><br clear="none"><br clear="none"></div><br><br></div> </div> </div> </div> </div></body></html>