On 1/27/13 12:15 PM, Kieu Thu Nguyen wrote:
@Justin,
Fmax=8.0226669e+00

OK, that looks good.

the system includes protein, lipid, water, ion Cl-

em.mdp file is

integrator               = steep
tinit                    = 0.0
dt                       = 0.02
nsteps                   = 50000
nstcomm                  = 1
nstxout                  = 5000
nstvout                  = 5000
nstfout                  = 0
nstlog                   = 1000
nstenergy                = 1000
nstxtcout                = 1000
xtc_precision            = 1000
nstlist                  = 1
ns_type                  = grid
pbc                      = xyz
rlist                    = 1.4
coulombtype              = Shift
rcoulomb_switch          = 0.0
rcoulomb                 = 1.2
epsilon_r                = 15
vdw_type                 = Shift
rvdw_switch              = 0.9
rvdw                     = 1.2
DispCorr                 = No
tcoupl                   = no
pcoupl                   = no
gen_vel                  = no
constraints              = none
constraint_algorithm     = Lincs
continuation         = no
lincs_order              = 4
lincs_warnangle          = 30


equi.mdp file is

integrator               = md
tinit                    = 0.0
dt                       = 0.03

Does a smaller time step work? I know the whole point of a MARTINI simulation is to use a 20-40 fs time step, but in my (very very limited) experience, nothing over 20 fs is consistently stable. Perhaps others with better experience can offer pointers.

-Justin

nsteps                   = 3000000
nstcomm                  = 1
comm-grps         =
nstxout                  = 5000
nstvout                  = 5000
nstfout                  = 0
nstlog                   = 1000
nstenergy                = 1000
nstxtcout                = 1000
xtc_precision            = 100
xtc-grps                 =
energygrps               =
nstlist                  = 10
ns_type                  = grid
pbc                      = xyz
rlist                    = 1.2
coulombtype              = Shift
rcoulomb_switch          = 0.0
rcoulomb                 = 1.2
epsilon_r                = 15
vdw_type                 = Shift
rvdw_switch              = 0.9
rvdw                     = 1.2
DispCorr                 = No
tcoupl                   = Berendsen
tc-grps                  = Protein DSPC Ion_W
tau_t                    = 1.5 1.5 1.5
ref_t                    = 310 310 310
Pcoupl                   = Berendsen
Pcoupltype               = semiisotropic
tau_p                    = 3.0 3.0
compressibility          = 3e-4 3e-4
ref_p                    = 1.0 1.0
gen_vel                  = no
constraints              = none
constraint_algorithm     = Lincs
continuation             = no
lincs_order              = 4
lincs_warnangle          = 30

Thanks so much for any help !
Regards,
KT


On Sun, Jan 27, 2013 at 8:26 AM, Justin Lemkul <[email protected]> wrote:



On 1/26/13 8:17 PM, Kieu Thu Nguyen wrote:

Thank Tsjerk so much !
But after being minimized 50000 steps and equilibrated 90 ns, there are
some bonds in the system that rotate more than 30 degrees.
I applied tips for blew up system as you advised. But the system does not
achieve balance.
Should i carry out more many steps for minimization ? or minimize many
times ? to get more equilibrated system.


I would say that 50000 steps of minimization is far more than is normally
necessary.  What Fmax do you achieve at the end of EM?  What is in the
system? What is in your .mdp file?  Systems can randomly crash if the model
physics breaks due to incorrect .mdp settings or an unstable topology.

-Justin


  On Thu, Jan 24, 2013 at 11:13 PM, Tsjerk Wassenaar <[email protected]
wrote:

  Hi KT,

This is caused by another problem. Your system blew up. Check messages
before this one, and check the log for LINCS warnings.

Cheers,

Tsjerk

On Thu, Jan 24, 2013 at 9:11 AM, Kieu Thu Nguyen <[email protected]

wrote:


  Dear All,

My MD simulation  has an error

Warning: Only triclinic boxes with the first vector parallel to the

x-axis

and the second vector in the xy-plane are supported.
           Box (3x3):
              Box[    0]={         nan,          nan,          nan}
              Box[    1]={         nan,          nan,          nan}
              Box[    2]={         nan,          nan,          nan}
           Can not fix pbc.

I searched on Gromacs-errors web, but i did not see this error.
How can i fix it ?

Thanks and regards,
KT
--
gmx-users mailing list    [email protected]
http://lists.gromacs.org/**mailman/listinfo/gmx-users<http://lists.gromacs.org/mailman/listinfo/gmx-users>
* Please search the archive at
http://www.gromacs.org/**Support/Mailing_Lists/Search<http://www.gromacs.org/Support/Mailing_Lists/Search>before
 posting!
* Please don't post (un)subscribe requests to the list. Use the
www interface or send it to [email protected].
* Can't post? Read 
http://www.gromacs.org/**Support/Mailing_Lists<http://www.gromacs.org/Support/Mailing_Lists>




--
Tsjerk A. Wassenaar, Ph.D.

post-doctoral researcher
Biocomputing Group
Department of Biological Sciences
2500 University Drive NW
Calgary, AB T2N 1N4
Canada
--
gmx-users mailing list    [email protected]
http://lists.gromacs.org/**mailman/listinfo/gmx-users<http://lists.gromacs.org/mailman/listinfo/gmx-users>
* Please search the archive at
http://www.gromacs.org/**Support/Mailing_Lists/Search<http://www.gromacs.org/Support/Mailing_Lists/Search>before
 posting!
* Please don't post (un)subscribe requests to the list. Use the
www interface or send it to [email protected].
* Can't post? Read 
http://www.gromacs.org/**Support/Mailing_Lists<http://www.gromacs.org/Support/Mailing_Lists>


--
==============================**==========

Justin A. Lemkul, Ph.D.
Research Scientist
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.**vt.edu/Pages/Personal/justin<http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin>

==============================**==========

--
gmx-users mailing list    [email protected]
http://lists.gromacs.org/**mailman/listinfo/gmx-users<http://lists.gromacs.org/mailman/listinfo/gmx-users>
* Please search the archive at http://www.gromacs.org/**
Support/Mailing_Lists/Search<http://www.gromacs.org/Support/Mailing_Lists/Search>before
 posting!
* Please don't post (un)subscribe requests to the list. Use the www
interface or send it to [email protected].
* Can't post? Read 
http://www.gromacs.org/**Support/Mailing_Lists<http://www.gromacs.org/Support/Mailing_Lists>


--
========================================

Justin A. Lemkul, Ph.D.
Research Scientist
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin

========================================
--
gmx-users mailing list    [email protected]
http://lists.gromacs.org/mailman/listinfo/gmx-users
* Please search the archive at 
http://www.gromacs.org/Support/Mailing_Lists/Search before posting!
* Please don't post (un)subscribe requests to the list. Use the www interface or send it to [email protected].
* Can't post? Read http://www.gromacs.org/Support/Mailing_Lists

Reply via email to