<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><BR><DIV><DIV>On 5 Oct 2007, at 17:18, Luca 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">A this moment I want only real part...</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">EWALD NONE=standard real-space coulomb potential is computed together</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">with the non-bonded contributions.</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">am I right?</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px"><BR></P></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV><DIV>I checked in the source code now.. and if you use EWALD_TYPE NONE you're just</DIV><DIV>doing the coulomb potential 1/r together with the non-bonded.. in this case it's only the minimum image </DIV><DIV>that is taken into account...</DIV><DIV>If you use PERIODIC NONE in the cell it's not even considered the minimum image but the position of the particles as</DIV><DIV>they are given in input..</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>The question is: are you sure you really want to do that? </DIV><BR><BLOCKQUOTE type="cite"><P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px"></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">There are a lot of knobs to be adjusted!!!!!</FONT></P> </BLOCKQUOTE></DIV><BR><DIV>This is the price you have to pay to have lots of capabilities.. codes like amber/namd/charmm (though they are</DIV><DIV>for sure faster than we are) are quite sticked into bio stuff.. </DIV><DIV>Just a remark: what you're trying to do (if that's really what you want) could never be done with the codes mentioned above...</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Teo</DIV></BODY></HTML>