Dear All<br>I am using this .mdp file and I recived the below warnings,I can&#39;t solve that.<br><br><br>title                    = NPT<br>define                   = <br>integrator               = md<br>tinit                    = 0<br>
dt                       = 0.002<br>nsteps                   = 500000<br>nstcomm                  = 1<br>comm-grps                = protein non-protein<br>niter                    = 20<br>nstxout                  = 5000<br>
nstvout                  = 5000<br>nstfout                  = 0<br>nstlog                   = 5000<br>nstenergy                = 250<br>nstxtcout                = 250<br>xtc-precision            = 1000<br>xtc_grps                 = protein non-protein<br>
energygrps               = Protein  non-protein<br>nstlist                  = 5<br>ns_type                  = grid<br>pbc                      = xyz<br>rlist                    = 1.4<br>domain-decomposition     = no<br>coulombtype              = PME<br>
rcoulomb-switch          = 0<br>rcoulomb                 = 1.4<br>epsilon-r                = 1<br>vdw-type                 = Cut-off<br>rvdw-switch              = 0<br>rvdw                     = 1.4<br>DispCorr                 = EnerPres<br>
fourierspacing           = 0.12<br>fourier_nx               = 0<br>fourier_ny               = 0<br>fourier_nz               = 0<br>pme_order                = 4<br>ewald_rtol               = 1e-05<br>epsilon_surface          = 0<br>
optimize_fft             = no<br>tcoupl                   = Nose-hoover<br>tc-grps                  = Protein     non-protein<br>tau_t                    = 0.1  0.1<br>ref_t                    = 300  300<br>Pcoupl                   = Parrinello-Rahman<br>
Pcoupltype               = Isotropic<br>tau_p                    = 1.0<br>compressibility          = 4.5e-5<br>ref_p                    = 1.0<br>annealing                = no<br>gen_vel                  = yes<br>gen_temp                 = 310<br>
gen_seed                 = 173529<br>constraints              = all-bonds<br>constraint-algorithm     = Lincs<br>unconstrained-start      = no<br>lincs-order              = 4<br>lincs-warnangle          = 30<br>morse                    = no<br>
<br>my sytem is protein-ligand,I want to generate a NPT.<br>the result was:<br><br>Step 0, time 0 (ps)  LINCS WARNING<br>relative constraint deviation after LINCS:<br>rms 0.002537, max 0.119994 (between atoms 5293 and 5294)<br>
bonds that rotated more than 30 degrees:<br> atom 1 atom 2  angle  previous, current, constraint length<br>starting mdrun &#39;Protein in water&#39;<br>500000 steps,   1000.0 ps.<br><br>Step 0, time 0 (ps)  LINCS WARNING<br>
relative constraint deviation after LINCS:<br>rms 1503.633433, max 55362.878906 (between atoms 5289 and 5290)<br>bonds that rotated more than 30 degrees:<br> atom 1 atom 2  angle  previous, current, constraint length<br>   5264   5263   41.7    0.1143   0.1261      0.1140<br>
   5293   5294   82.7    0.1221 2612.9744      0.1090<br>   5291   5293   77.2    0.1517 6082.6147      0.1390<br>   5291   5292  101.0    0.1117 1518.6106      0.1090<br>   5289   5291   87.7    0.1353 6891.8911      0.1390<br>
   5289   5290   88.4    0.1437 7529.4878      0.1360<br>   5289   5287   88.4    0.1456 7540.4873      0.1390<br>   5287   5288   89.7    0.1092 381.5114      0.1090<br>   5285   5287   92.3    0.1395 354.9220      0.1390<br>
   5285   5286  123.8    0.1101  44.8448      0.1090<br>   5284   5293   89.0    0.1478 4605.1763      0.1390<br>   5284   5285   79.3    0.1402 173.5627      0.1390<br>   5278   5279   78.9    0.1529   1.1270      0.1530<br>
   5277   5278  122.9    0.1545  13.1423      0.1530<br>   5276   5284   84.9    0.1422 159.0098      0.1390<br>   5276   5277   68.4    0.1543  90.8248      0.1530<br>   5276   5275   39.5    0.1439  72.5216      0.1430<br>
   5274   5275  103.7    0.1436  21.6028      0.1430<br>   5273   5274  108.5    0.1394   3.3421      0.1390<br>   5276   5272   45.7    0.1402  80.6795      0.1390<br>   5272   5273  127.3    0.1340  14.2401      0.1330<br>
   5272   5270   69.8    0.1336  12.6250      0.1330<br>   5270   5271  113.3    0.1092   0.2530      0.1090<br>   5268   5270  104.6    0.1391   0.2718      0.1390<br>   5268   5269   44.4    0.1091   0.1636      0.1090<br>
   5273   5266   58.5    0.1342  14.0125      0.1330<br>   5265   5268   36.5    0.1394   0.1769      0.1390<br><br>Back Off! I just backed up step0b.pdb to ./#step0b.pdb.2#<br><br>Back Off! I just backed up step0c.pdb to ./#step0c.pdb.2#<br>
Wrote pdb files with previous and current coordinates<br>step 0Warning: 1-4 interaction between 5264 and 5273 at distance 13.965 which is larger than the 1-4 table size 2.400 nm<br>These are ignored for the rest of the simulation<br>
This usually means your system is exploding,<br>if not, you should increase table-extension in your mdp file<br>or with user tables increase the table size<br><br>Please let me know the solution.<br>Thanks in advance<br><br>
<br><br><br><br>