<html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div>Dear all,
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<div> </div>
<div>I have a question concerning tabulated potentials:</div>
<div>My System consists of three different particles P_1, P_2 and P_3 and I would like to use </div>
<div>tabulated potentials for the bonded as well as the nonbonded interactions.</div>
<div>Runing mdrun produces both:</div>
<div>1.) various warnings:</div>
<div> </div>
<div>WARNING: For the 239 non-zero entries for table 0 in table_P_1_P_1.xvg the forces deviate on average 164% from minus the numerical derivative of the potential</div>
<div>
<div>WARNING: For the 168 non-zero entries for table 1 in table_P_1_P_1.xvg the forces deviate on average 164% from minus the numerical derivative of the potential</div>
<div>WARNING: For the 168 non-zero entries for table 1 in table_P_1_P_2.xvg the forces deviate on average 164% from minus the numerical derivative of the potential</div>
<div>WARNING: For the 168 non-zero entries for table 1 in table_P_1_P_3.xvg the forces deviate on average 164% from minus the numerical derivative of the potential</div>
<div>WARNING: For the 168 non-zero entries for table 1 in table_P_2_P_2.xvg the forces deviate on average 164% from minus the numerical derivative of the potential</div>
<div>WARNING: For the 168 non-zero entries for table 1 in table_P_2_P_3.xvg the forces deviate on average 164% from minus the numerical derivative of the potential<br/>
WARNING: For the 168 non-zero entries for table 1 in table_P_3_P_3.xvg the forces deviate on average 164% from minus the numerical derivative of the potential<br/>
WARNING: For the 199 non-zero entries for table 0 in table_b0.xvg the forces deviate on average 164% from minus the numerical derivative of the potential<br/>
WARNING: For the 199 non-zero entries for table 0 in table_b1.xvg the forces deviate on average 244% from minus the numerical derivative of the potential<br/>
WARNING: For the 199 non-zero entries for table 0 in table_b2.xvg the forces deviate on average 165% from minus the numerical derivative of the potential<br/>
WARNING: For the 179 non-zero entries for table 0 in table_a0.xvg the forces deviate on average 193% from minus the numerical derivative of the potential<br/>
WARNING: For the 179 non-zero entries for table 0 in table_a1.xvg the forces deviate on average 193% from minus the numerical derivative of the potential<br/>
WARNING: For the 179 non-zero entries for table 0 in table_a2.xvg the forces deviate on average 193% from minus the numerical derivative of the potential<br/>
WARNING: For the 177 non-zero entries for table 0 in table_a3.xvg the forces deviate on average 193% from minus the numerical derivative of the potential<br/>
WARNING: For the 358 non-zero entries for table 0 in table_d0.xvg the forces deviate on average 193% from minus the numerical derivative of the potential<br/>
WARNING: For the 356 non-zero entries for table 0 in table_d1.xvg the forces deviate on average 193% from minus the numerical derivative of the potential<br/>
WARNING: For the 358 non-zero entries for table 0 in table_d2.xvg the forces deviate on average 193% from minus the numerical derivative of the potential<br/>
WARNING: For the 358 non-zero entries for table 0 in table_d3.xvg the forces deviate on average 193% from minus the numerical derivative of the potential<br/>
WARNING: For the 356 non-zero entries for table 0 in table_d4.xvg the forces deviate on average 196% from minus the numerical derivative of the potential</div>
<div> </div>
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<div>2.) and a segmentation fault:</div>
<div>
<div>step 0 segmentation fault.</div>
<div> </div>
<div>My question:</div>
<div>Why is there so much deviation between the forces, calculated by gromacs and the numerical deviative of the potential?</div>
<div>I have no impact on that calculation, does I?</div>
<div>The values of the force specified in the table are right for sure.</div>
<div> </div>
<div>It is possiible that the segmentation fault results from this "force-problem" is it?</div>
<div> </div>
<div>Tank you very much in advance.</div>
Best,
<div>Liz</div>
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