<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div>Hi,</div><div> I am trying to use a table potential implementing Weeks-Chandler-Anderson (WCA) interaction between a solute and all atoms of a solvent like TIP3P water ( with nonzero interaction in the Hydrogen atoms) . But, I am having a trouble in specifying energy groups required for table potential. </div><div>Here is the problem:</div><div> I have two atom types in water : OW and HW. and one atom type in solute : POL</div><div><br></div><div>Now, I want to use two Table potentials with WCA interactions between a) POL & HW and b) POL & OW </div><div>So, I created two table potential files: table_POL_HW.xvg and table_POL_OW.xvg</div><div><br></div><div>and then</div><div>in the .mdp file, I specified </div><div>energygrps = POL OW HW </div><div>energygrps_table = POL OW POL
HW</div><div><br></div><div>But, compiling the .mdp file using grompp ( version 4.5.4) gives me following error</div><div><div>"Fatal error: </div><div>atoms 33 and 34 in charge group 1 of molecule type 'SOL' are in different energy groups"</div><div><br></div><div>Clearly, using OW and HW as separate energy groups is causing the problem.</div><div>So, I am looking for an option on how I can use the table potential between solute and each atoms of solvent.</div><div><br></div><div>Any help will be appreciated.</div><div>Sanku</div></div></div></body></html>