[gmx-users] parameters for output control

[mohammad agha]

Dear Gromacs Users, 

I have one problem about the way of computation in the Gromacs with frame and time. (I work with MARTINI CG) 
I have one md.mdp file that the parameters of output control in it is as follows: 
nsteps = 30000000 
dt = 0.030 
; Output control 
nstxout = 2000 
nstvout = 2000 
nstenergy = 2000 
nstlog = 2000 
nstxtcout = 2000 
xtc_precision = 1000 
Consequently, total time of my system is 900000 ps.When I want to obtaine some information about my system for example RDF by g_rdf command, computation of Gromacs perfome as follows: 
Reading frame 200 time 12000.000 
.................300 
.................400 
.................500 
.................600 
.................700 
........... 
........... 
........... 
Reading frame 2000 time 120000.000 
.................3000 
.................4000 
.................5000 
.................6000 
.................7000 
........... 
........... 
........... 
Last frame 15000 time 900000.000 
It means that until frame 2000 reading is 100 to 100 in frames and from 2000 to end, it is 1000 to 1000. 
Also, I did with this parameters: 
; Output control 
nstxout = 200 
nstvout = 200 
nstenergy = 100 
nstlog = 200 
nstxtcout = 200 
xtc_precision = 100 
but the result of reading the frames was the same previous. 
I want to Gromacs read frames 100 to 100 not 1000 to 1000, because I find problem when I use -b in g_rdf command. for eaxample, with -b 80000, reading is only until 860040 ps, Reading frame 13000 time 860040.000 ,not until end of simulation (900000). 
Also, I want to have smaller systems with smaller volume by convert 2000 to 10000 for parameters for output control but I want reading from frame for computation of properties become 100 frames to 100 frames or 10 frames to 10 frames. 

May I ask you to help me, Please? 
Thank you very much in advance. 
Best Regards 
Sara