MD simulation analysis TSD

From Bioinformatikpedia
Revision as of 21:33, 30 August 2012 by Reeb (talk | contribs) (General)


<figtable id="tbl:generalstats">

Table 1: Runtime statistics for the Gromacs simulations. CPU denotes the number of allocated CPUs during the simulation. ns/day and days/s values are based on this number and not normalised.

Model CPU Runtime ns/day days/s
style="border-style: solid; border-width: 0 0 0 0" | Wildtype 16 13h52 17.3 3896
R178H 12 19h03 12.6 5354
P182L 32 07h08 33.6 2006


<xr id="tbl:generalstats"/> shows general statistics about the three simulations. It should be noted that the output of gmxcheck does not account for the number of CPUs used in the calculation and only reports the real time that passed. Normalizing the runtimes by the number of CPUs involved yields that the Wildtype and P182L mutation completed within 4 hours. R178H took 4 hours longer, however the difference is negligible, considering that they were not done in a testing environment and it is assumed that all CPUs could maintain equal load throughout the runs. In fact Gromacs reports a particularly high 12% of the time being lost due to PP/PME imbalance.




<figtable id="tab:pressure">

WT, Average:4.077
R178H, Average:1.647
P182L, Average:-0.3182
Table TODO: Pressure oscillations for the three simulations. A cumulative average is shown in red.


<xr id="tab:pressure"/> shows the pressure oscillations for the three simulations. As can be seen per-frame values differ by several 100 bar, as to be expected <ref name="gromacsmanualpressure"></ref>. More importantly the average shows convergence in every simulation and does not undergo any major changes towards the end of the simulations. The final average pressure also lies close to 0 in all cases.


<figtable id="tab:temperature">

WT, Average: 297.9
R178H Average: 297.9
P182L Average: 297.9
Table TODO: Temperature changes during the simulations. A cumulative average is shown in red.


<xr id="tab:temperature"/> shows the temperature variances during the simulations. The mutations both show higher extreme values than the wildtype structure, especially P182L. The average however remains exactly the same for all simulations, which is the expected behavior after a period of time passed <ref name=""></ref>. The fact the all simulations arrive at the same value also supports that the simulations went well and arrived at the correct temperature.

Potential Energy

<figtable id="tab:potentialenergy">

WT Average: -884100
R178H Average: -884100
P182L Average: -884400
Table TODO: Potential energy changes during the simulations. A cumulative average is shown in red.


<xr id="tab:potentialenergy"/> shows the fluctuations of potential energy during the simulations. As can be seen, during all simulations it is globally decreasing and the final averages of all three runs are similar.

Total Energy

<figtable id="tab:totenergy">

Average: -725700
Average: -725500
Average: -725500
Table TODO: Total energy change during simulations.


<xr id="tab:totenergy"/> shows the total energy which is composed of the potential energy shown before and the kinetic energy <ref name="gromacstotenergy"></ref>. It also globally decreases for all runs and the final averages are very similar which leads to the conclusion, that the kinetic energy behaves similarly. Given that the WT behaves in the same way than the mutations one cannot say that the mutations have an effect on the total energy.