Dear Guru;<br>Please give any suggestion or hint on this problem<br>I do MD for a polymer chain (about 1000 atoms) in water (SPC) with OPLSAA <br>according to the alogoritm<br>1 em in vacoom<br>2. solvate with water<br>3. do em and position restrain
<br>4. do NVT MD with berendsen thermostan<br>with dt=0.001ps and trajectory length 5ns<br>Coulomb, VdW=cut-off<br>rlist=1.2<br>r_coulomb=1.4<br>r_vdw=1.4<br><br>the aim of simulation is to find coil to globule transition
<br>I do NVT under different temperatures (from 280 to 340 K) <br>and really find the temperature after what my polymer become a globule (about 310 K)<br>it was the result that i expact =)<br>but when I do MD with the temperature 315-everything is ok,it is a globule, 320-ok.
<br>but with the higher tempetature it's didn't become a globule. and it's not what i'm expacting.<br><br>may be where is a mistake in my algorithm. <br>perhaps i've to do an annealing MD or something else?
<br><br><br clear="all"><br>-- <br>Dmitriy Golubovsky