<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "> Yes unfortunately there's a misunderstanding. <div>A GHOST atom is not what you think of.</div><div>A ghost for CP2K is an atom with no nuclear charge but with a basis set (which you can specify). This kind of GHOST atoms</div><div>are used mostly for BSSE: read carefully the online reference input: <a href="http://cp2k.berlios.de/input/InputReference~__ROOT__~FORCE_EVAL~SUBSYS~KIND.html#GHOST">http://cp2k.berlios.de/input/InputReference~__ROOT__~FORCE_EVAL~SUBSYS~KIND.html#GHOST</a></div><div><br class="webkit-block-placeholder"></div><div>Of course you can put BASIS_SET NONE and in this case what you have is essentially NOTHING (i.e. no electrons, no basis set and no pseudo).</div><div><br class="webkit-block-placeholder"></div><div>What you want to do can be done easily or using BASIS_SET NONE (and specifying it GHOST, see above) or just avoid the mapping of that atom </div><div>in the free energy module. Both methods (if properly done) will lead to the same numbers.</div><div><br class="webkit-block-placeholder"></div><div>Teo</div><div><br><div><div>On 27 Aug 2008, at 17:37, Jun Cheng wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; ">POTENTIAL is needed? Or I misunderstand something?</span></blockquote></div><br></div></body></html>