<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; ">Yep,<DIV>Correct picture! ;-)</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Teo</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>P.s.: at the moment in the QMMM-SE the interactions SE-SE are neglected.. this will be changes in the next months, including the</DIV><DIV>possibility to have also the SE-SE interaction</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>For DFT (GPW and GAPW) methods it is already available the possibility to have the QM-QM interactions within a QMMM calculation.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><DIV><DIV>On 19 Sep 2007, at 12:58, ivan wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">So this means, that Semi-Empirical methods can be used even</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">periodically, if they're embedded in a calssical environment? Of</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">course, one neglects the SE-SE interactions between periodic images,</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">but if the box around the QM part is big enough it does not change</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">things too much.. Is that correct? Or would it be simply another</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">cluster calculation (with significantly more atoms due to reduced</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">computational intensitiy of the classical model)?</FONT></P> </BLOCKQUOTE></DIV><BR></DIV></BODY></HTML>