>From the information you have provided, nothing is clear to me. Which method would you like to use, umbrella sampling or Thermodynamic integration ? If you can tell me this, i may help you. Regards, Sandeep <div class="gmail_quote">On Sat, Dec 10, 2011 at 8:59 PM, Ross, Sun <<a href="mailto:sunshou...@yahoo.com.cn">sunshou...@yahoo.com.cn</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> Hi everybody, Could anyone tell me how to get free energy with constrained MD? The input file in &MOTION like this: &CONSTRAINT &COLLECTIVE COLVAR 1 INTERMOLECULAR TARGET [angstrom] 1.2 TARGET_GROWTH [angstrom] 0.01 TARGET_LIMIT [angstrom] 3.0 &END COLLECTIVE &END CONSTRAINT Thank you in advance. Best regards, sun -- You received this message because you are subscribed to the Google Groups "cp2k" group. To post to this group, send email to <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>. To unsubscribe from this group, send email to <a href="mailto:cp2k%2Bun...@googlegroups.com">cp2k+uns...@googlegroups.com</a>. For more options, visit this group at <a href="http://groups.google.com/group/cp2k?hl=en" target="_blank">http://groups.google.com/group/cp2k?hl=en</a>. </blockquote></div>