Hi All,<br> I'm trying to run free energy simulations for a linkage change in an oligosaccharide when bound to its protein.<br>The linkage changes from beta 1-4 to beta 1-3. I followed the tutorial by Prof Mobley.<br>
For the lambda values I took 0 to 1 at intervals of 0.05. The values of dVpot/dlambda from 0.00 to 0.95 seem to be in the range of E3-4. But when I check the values of dVpot/dlambda for lambda = 1, it goes from E2 to E24 at the end. This is only for the LBFGS minimization.<br>
Does any one suspect a mistake in my topology or my approach?<br>Thanks for your time.<br><br><br>Sample .log file of lambda = 1 is pasted below.<br><br> Step Time Lambda<br> 100 100.00000 1.00000<br>
<br> Energies (kJ/mol)<br> Bond Angle Proper Dih. Ryckaert-Bell. LJ-14<br> 1.06593e+04 8.20816e+03 2.93142e+02 4.26304e+03 8.30759e+03<br> Coulomb-14 LJ (SR) Disper. corr. Coulomb (SR) Coul. recip.<br>
4.13439e+04 1.92653e+05 -1.08257e+04 -1.46637e+06 -2.72128e+05<br> Potential Pressure (bar) dVpot/dlambda dEkin/dlambda dG/dl constr.<br> -1.48359e+06 -4.15979e+03 -1.01327e+15 0.00000e+00 0.00000e+00<br>
<br> Step Time Lambda<br> 101 101.00000 1.00000<br><br> Energies (kJ/mol)<br> Bond Angle Proper Dih. Ryckaert-Bell. LJ-14<br> 1.06477e+04 8.21153e+03 2.93330e+02 4.26328e+03 8.31182e+03<br>
Coulomb-14 LJ (SR) Disper. corr. Coulomb (SR) Coul. recip.<br> 4.13437e+04 1.92648e+05 -1.08257e+04 -1.49776e+06 -2.72128e+05<br> Potential Pressure (bar) dVpot/dlambda dEkin/dlambda dG/dl constr.<br>
-1.51500e+06 -4.33201e+03 -2.78144e+18 0.00000e+00 0.00000e+00<br><br> Step Time Lambda<br> 103 103.00000 1.00000<br><br> Energies (kJ/mol)<br> Bond Angle Proper Dih. Ryckaert-Bell. LJ-14<br>
1.06776e+04 8.21126e+03 2.93576e+02 4.26328e+03 8.31168e+03<br> Coulomb-14 LJ (SR) Disper. corr. Coulomb (SR) Coul. recip.<br> 4.13437e+04 1.92656e+05 -1.08257e+04 -1.76397e+06 -2.72128e+05<br>
Potential Pressure (bar) dVpot/dlambda dEkin/dlambda dG/dl constr.<br> -1.78117e+06 -5.80136e+03 -1.76071e+24 0.00000e+00 0.00000e+00<br><br><br><br><br>Regards<br>Sai<br><br>