Hello,

I have ran a energy minimization, followed by nvt, followed by md run. My md run mdp (ie., md.mdp) has

dt = 0.002, nsteps = 30000000 ; [0.002 * 30000000 = 60000 ps (60 ns)]

nstxout = 5000 ; save coordinates every 10.0 ps

nstvout = 5000 ; save velocities every 10.0 ps

nstenergy = 5000 ; save energies every 10.0 ps

nstlog= 5000 ; update log file every 10.0 ps

nstxout-compressed = 5000 ; save compressed coordinates every 10.0 ps

                                   ; nstxout-compressed replaces nstxtcout

This simulation i have ran for 60 ns. 

Now i need extend the simulation for another 20ns, but with the change in md.mdp file as:-

dt = 0.001, and nsteps = 20000000

nstxout= 1000 ; save coordinates every 1.0 ps

nstvout= 1000 ; save velocities every 1.0 ps

nstenergy = 1000 ; save energies every 1.0 ps

nstlog = 1000 ; update log file every 1.0 ps

nstxout-compressed =1000; save compressed coordinates every 1.0 ps;                                                ;nstxout-compressed replaces nstxtcout

ie., i want the  dt time step of 0.001 and the outputs (nstxout,nstvout,etc.,) which can save the coordinates for every 1.0ps, for the 20ns md run.

And then i need to have a  complete run of total 80ns [(60ns of the 1st mdrun  of dt=0.002*30000000) + (20ns of the 2nd mdrun of dt=0.001*20000000)].

How can i do this..??

Thank you.