Re: [gmx-users] profiles az a function of z

2009-10-16 Thread Mark Abraham

Paymon Pirzadeh wrote:

Well, the main purpose is to average the energy or any desired property
along any desired coordinate axis. simple binning of the box will do the
job, but I was wondering if this can be done in general with gromacs
post simulation tools.


No, there is no general way to do this. Individual tools might let you 
construct various analysis "groups" according to some geometric 
criterion, but in general you need to use atomic indices in .ndx files.


Mark
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[gmx-users] reduced units

2009-10-16 Thread lammps lammps
Dear,

I want to do stochastic simulations in the framework of Langevin dynamics
using Gromacs with the reduced units.  The questions are:

1. How to turn on the reduced units? Is there any parameters for setting?

2. If I use the reduced temperature of 1, should the ref_t in the .mdp file
be the 120.2717 ?  Right?

3. I create the force field(.itp and .top) within the reduced units myself.
Are there any suggestion for avoiding errors?

Thanks in advance.


-- 
wende
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Re: [gmx-users] Example file for DNA

2009-10-16 Thread Justin A. Lemkul



David Crosby wrote:

Hello fellow GROMACS users!

I've been having a heck of a time with the reformatting of a DNA molecule
into a GROMACS-compatible format.  I know that residues (bases) must be
renamed to DTHR, etc., though it would be endlessly helpful if someone could
please send me an example pdb or gmx file I can use as reference.  Better
yet, if anyone has a nifty program that will reformat a nucleic acid model
into the GROMACS format, that would answer my prayers!  The duplex I'm
working with is only 21nt, so it's not insane to have to modify the file by
hand...



A simple Perl script can make substitutions, or you can use a text editor like 
vi or a command like sed.  In about 4 commands, the whole file can be re-named. 
 In vi, for example:


:1,$s/DT  /DTHY/g

...and all of your thymines are re-named (note the spacing is important).

-Justin


Thanks in advance!
Dave Crosby

University of California, Irvine
Dept of Pathology and Laboratory Medicine

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ICTAS Doctoral Scholar
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin


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[gmx-users] Example file for DNA

2009-10-16 Thread David Crosby
Hello fellow GROMACS users!

I've been having a heck of a time with the reformatting of a DNA molecule
into a GROMACS-compatible format.  I know that residues (bases) must be
renamed to DTHR, etc., though it would be endlessly helpful if someone could
please send me an example pdb or gmx file I can use as reference.  Better
yet, if anyone has a nifty program that will reformat a nucleic acid model
into the GROMACS format, that would answer my prayers!  The duplex I'm
working with is only 21nt, so it's not insane to have to modify the file by
hand...

Thanks in advance!
Dave Crosby

University of California, Irvine
Dept of Pathology and Laboratory Medicine

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Re: [gmx-users] profiles az a function of z

2009-10-16 Thread Paymon Pirzadeh
Well, the main purpose is to average the energy or any desired property
along any desired coordinate axis. simple binning of the box will do the
job, but I was wondering if this can be done in general with gromacs
post simulation tools.

Payman


On Fri, 2009-10-16 at 16:05 -0400, Justin A. Lemkul wrote:
> 
> Paymon Pirzadeh wrote:
> > Hello,
> > In a simulation, how is it possible to extract the profiles e.g.
> > potential as a function of z (coordinate axis of box)?
> > 
> 
> g_potential can do this for electrostatic potential, but I don't know about 
> anything else.  I don't think it is a trivial question to decompose the 
> potential of the entire system along any axis.
> 
> -Justin
> 
> > Payman
> > 
> > ___
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Re: [gmx-users] profiles az a function of z

2009-10-16 Thread Justin A. Lemkul



Paymon Pirzadeh wrote:

Hello,
In a simulation, how is it possible to extract the profiles e.g.
potential as a function of z (coordinate axis of box)?



g_potential can do this for electrostatic potential, but I don't know about 
anything else.  I don't think it is a trivial question to decompose the 
potential of the entire system along any axis.


-Justin


Payman

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--


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


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[gmx-users] GROMACS scaling at 64 cpus

2009-10-16 Thread Berk Hess

Hi,

This of course depends very much on all your settings.
Up to now I have found that a 3:1 ratio is optimal for rectangular boxes,
whereas 2:1 is optimal for rhombic dodecahedra.
64 cores was the limit for the benchmark system on that hardware,
so I had to increase the number of PME beyond the 1/3 to get optimal 
performance.

Berk


Hi,

I recently got a nice Sun X6275 blade system 
http://nf.nci.org.au/facilities/vayu/hardware.php (ok, not just for me!) 
whose hardware ought to be better, but very comparable to that used in 
the GROMACS 4 paper (http://pubs.acs.org/doi/abs/10.1021/ct700301q). 
Figure 5 there demonstrates good scaling out to 38 cpus, but it drops 
away from linearity by 64. On the same test system on this hardware (pdf 
attached; blue arrow is ideal linearity) the drop-off is still about the 
same.

For 64 cpus, that paper reports using 28 PME nodes, which is an 
appreciably lower ratio than the 2:1 for the rest of the tests. On my 
hardware I found that that choice cost about 30% performance, compared 
with a more reasonable use of 19 PME nodes (64 vs 86 ns/day, pdf 
attached). Is that 28 a typo for 18?

Mark

  
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[gmx-users] profiles az a function of z

2009-10-16 Thread Paymon Pirzadeh
Hello,
In a simulation, how is it possible to extract the profiles e.g.
potential as a function of z (coordinate axis of box)?

Payman

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Re: [gmx-users] Lipid-protein tutorial by Lemkul

2009-10-16 Thread seunghwan lee
Hi Justin,

Thank you for your answer. It made me to think again and I found the 
source of the problem (silly mistake). Thanks again!

Seunghwan Lee


--- On Fri, 10/16/09, Justin A. Lemkul  wrote:

> From: Justin A. Lemkul 
> Subject: Re: [gmx-users] Lipid-protein tuturial by Lemkul
> To: "Discussion list for GROMACS users" 
> Date: Friday, October 16, 2009, 11:45 AM
> 
> 
> seunghwan lee wrote:
> > Hi
> > 
> > I am new to Gromacs and going through some tutorials.
> I am working on lipid-protein tutorial given by Justin
> Lemkul and I am stuck with the very first step. When I
> execute pdb2gmx to generate .top file and .pdb without
> hydrogen,
> > 
> > pdb2gmx -f KALP-15_princ.pdb -o KALP-15_processed.gro
> -ignh -ter -water spc
> > 
> > I got the following message:
> > 
> >
> ---
> > Program pdb2gmx, VERSION 4.0.4
> > Source code file: pgutil.c, line: 87
> > 
> > Fatal error:
> > Atom H not found in residue 17 while adding improper
> > 
> >
> ---
> > 
> > I made the correction to ffG53a6.rtp file as suggested
> by Justin, but apparently I am still having a problem with
> -NH2 residue (#17). Is there any other corrections I need to
> do in order to make this work?
> > 
> 
> No other correction is necessary.  If you fixed the
> .rtp file correctly, you should not have any problems.
> 
> -Justin
> 
> > Thanks for your help!!
> > Seunghwan Lee
> > 
> > 
> >   
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> -- 
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> Ph.D. Candidate
> ICTAS Doctoral Scholar
> Department of Biochemistry
> Virginia Tech
> Blacksburg, VA
> jalemkul[at]vt.edu | (540) 231-9080
> http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin
> 
> 
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Re: [gmx-users] Error during NVT equillibration with nvt.log file

2009-10-16 Thread Justin A. Lemkul



ram bio wrote:

Dear Justin,

Thanks and I tried your suggestion, that is minimizing the system
without restraints and increasing the Fmax to 1000, the mdp file used
is as follows:



Note that I only suggested EM, not necessarily Fmax < 1000.  You original post 
contained an even lower Fmax, suggesting that you can do better than 1000.  The 
parameters in my tutorial are somewhat generic; you should alter them to suit 
your needs.




Please note that the headers of log files are typically unnecessary when posting 
the .mdp file.



please suggest me is it ok to remove the constraints and run the NVT
equillibration.



You can try it, but I doubt it will make a difference.  Your simulation is 
crashing before it is even starting, making it very difficult to diagnose.  You 
probably need to re-build the system, using as rigorous criteria as possible 
during the InflateGRO steps to ensure that you don't have any improper atomic 
overlap.  In my experience, if the simulation is failing at step 0, there is no 
hope for coaxing the system into working.  The configuration simply isn't 
reasonable.


-Justin


Thanks

Ram







On Fri, Oct 16, 2009 at 9:27 PM, Justin A. Lemkul  wrote:


ram bio wrote:

Dear Gromacs users,

I am doing protein in lipid-bilayer simulation and i am following the
procedure as per justin tutorial. I am able to insert the protein in
lipid bilayer and minimize the system as per Inflategro
procedure,during the total procedure the system was minimized in every
step.Then, I solvated and ionized sytem and minimized using the
following mdp file:

; minim.mdp - used as input into grompp to generate em.tpr
; Parameters describing what to do, when to stop and what to save
define = -DSTRONG_POSRES
integrator  = steep ; Algorithm (steep = steepest descent
minimization)
emtol   = 500.0 ; Stop minimization when the maximum
force < 1000.0 kJ/mol/nm
emstep  = 0.01  ; Energy step size
nsteps  = 5 ; Maximum number of (minimization)
steps to perform

; Parameters describing how to find the neighbors of each atom and how
to calculate the interactions
nstlist = 1 ; Frequency to update the neighbor
list and long range forces
ns_type = grid  ; Method to determine neighbor list
(simple, grid)
rlist   = 1.2   ; Cut-off for making neighbor list
(short range forces)
coulombtype = PME   ; Treatment of long range
electrostatic interactions
rcoulomb= 1.2   ; Short-range electrostatic cut-off
rvdw= 1.2   ; Short-range Van der Waals cut-off
pbc = xyz   ; Periodic Boundary Conditions (yes/no)

the output was as follows:

Steepest Descents converged to Fmax < 500 in 4770 steps
Potential Energy  = -3.8820288e+05
Maximum force =  4.4803549e+02 on atom 3573
Norm of force =  1.7854408e+01

As the potential energy and Fmax values were agreeable , I proceeded
to equillibrate the system using NVT.


Did you minimize the structure without restraints, prior to NVT?




 Angle   G96AngleProper Dih. Ryckaert-Bell.  Improper Dih.
   2.20077e+048.54042e+036.78950e+034.34650e+033.03266e+03
 LJ-14 Coulomb-14LJ (SR)  Disper. corr.   Coulomb (SR)
   4.76527e+035.50236e+048.36617e+06   -2.20019e+03   -4.46844e+05
  Coul. recip. Position Rest.  PotentialKinetic En.   Total Energy
  -1.65524e+051.07769e+017.85612e+065.88813e+105.88892e+10
 Conserved En.Temperature Pressure (bar)  Cons. rmsd ()
   5.88892e+102.23805e+081.21713e+093.10245e+01


In my experience, the combination of an astronomically high temperature and
a repulsive temperature is indicative of restraining an unrestrainable
starting structure.  Try the EM I suggested above.  Other than that, as I've
suggested before, see the Advanced Troubleshooting page I created in the
tutorial.

-Justin


Please help me to proceed further and let me know where are the
mistakes lying and how to overcome them.

Thanks in advance,

Ram
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Ph.D. Candidate
ICTAS Doctoral Scholar
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin


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Re: [gmx-users] Error during NVT equillibration with nvt.log file

2009-10-16 Thread ram bio
Dear Justin,

Thanks and I tried your suggestion, that is minimizing the system
without restraints and increasing the Fmax to 1000, the mdp file used
is as follows:

; minim.mdp - used as input into grompp to generate em.tpr
; Parameters describing what to do, when to stop and what to save
integrator  = steep ; Algorithm (steep = steepest descent 
minimization)
emtol   = 1000.0; Stop minimization when the maximum force < 
1000.0 kJ/mol/nm
emstep  = 0.01  ; Energy step size
nsteps  = 5 ; Maximum number of (minimization) steps to 
perform

; Parameters describing how to find the neighbors of each atom and how
to calculate the interactions
nstlist = 1 ; Frequency to update the neighbor list and 
long range forces
ns_type = grid  ; Method to determine neighbor list (simple, 
grid)
rlist   = 1.2   ; Cut-off for making neighbor list (short range 
forces)
coulombtype = PME   ; Treatment of long range electrostatic 
interactions
rcoulomb= 1.2   ; Short-range electrostatic cut-off
rvdw= 1.2   ; Short-range Van der Waals cut-off
pbc = xyz   ; Periodic Boundary Conditions (yes/no)

and the ouput is :

Steepest Descents converged to Fmax < 1000 in 1192 steps
Potential Energy  = -4.5402134e+05
Maximum force =  9.6024463e+02 on atom 3573
Norm of force =  3.8811920e+01

Later is used this as input for the NVT equillibration with the
following nvt.mdp file:

title   = NVT equilibration
define  = -DPOSRES  ; position restrain the protein
; Run parameters
integrator  = md; leap-frog integrator
nsteps  = 5 ; 2 * 5 = 100 ps
dt  = 0.002 ; 2 fs
; Output control
nstxout = 100   ; save coordinates every 0.2 ps
nstvout = 100   ; save velocities every 0.2 ps
nstenergy   = 100   ; save energies every 0.2 ps
nstlog  = 100   ; update log file every 0.2 ps
; Bond parameters
continuation= no; first dynamics run
constraint_algorithm = lincs; holonomic constraints
constraints = all-bonds ; all bonds (even heavy atom-H bonds) 
constrained
lincs_iter  = 1 ; accuracy of LINCS
lincs_order = 4 ; also related to accuracy
; Neighborsearching
ns_type = grid  ; search neighboring grid cels
nstlist = 5 ; 10 fs
rlist   = 1.2   ; short-range neighborlist cutoff (in nm)
rcoulomb= 1.2   ; short-range electrostatic cutoff (in nm)
rvdw= 1.2   ; short-range van der Waals cutoff (in nm)
; Electrostatics
coulombtype = PME   ; Particle Mesh Ewald for long-range 
electrostatics
pme_order   = 4 ; cubic interpolation
fourierspacing  = 0.16  ; grid spacing for FFT
; Temperature coupling is on
tcoupl  = V-rescale ; modified Berendsen thermostat
tc-grps = Protein DPPC SOL_CL-  ; three coupling groups - more accurate
tau_t   = 0.1   0.1 0.1 ; time constant, in ps
ref_t   = 323   323 323 ; reference temperature, one for each 
group, in K
; Pressure coupling is off
pcoupl  = no; no pressure coupling in NVT
; Periodic boundary conditions
pbc = xyz   ; 3-D PBC
; Dispersion correction
DispCorr= EnerPres  ; account for cut-off vdW scheme
; Velocity generation
gen_vel = yes   ; assign velocities from Maxwell distribution
gen_temp= 323   ; temperature for Maxwell distribution
gen_seed= -1; generate a random seed
; COM motion removal
; These options remove motion of the protein/bilayer relative to the
solvent/ions
nstcomm = 1
comm-mode   = Linear
comm-grps   = Protein_DPPC SOL_CL-

and the ouput nvt.log file is as under:

Input Parameters:
   integrator   = md
   nsteps   = 5
   init_step= 0
   ns_type  = Grid
   nstlist  = 5
   ndelta   = 2
   nstcomm  = 1
   comm_mode= Linear
   nstlog   = 100
   nstxout  = 100
   nstvout  = 100
   nstfout  = 0
   nstenergy= 100
   nstxtcout= 0
   init_t   = 0
   delta_t  = 0.002
   xtcprec  = 1000
   nkx  = 48
   nky  = 48
   nkz  = 60
   pme_order= 4
   ewald_rtol   = 1e-05
   ewald_geometry   = 0
   epsilon_surface  = 0
   optimize_fft = FALSE
   ePBC = xyz
   bPeriodicMols= FALSE
   bContinuation= FALSE
   bShakeSOR= FALSE
   etc  = V-rescale
   epc  = No
   epctype  = Isotropic
   tau_p

Re: [gmx-users] Error during NVT equillibration with nvt.log file

2009-10-16 Thread Justin A. Lemkul



ram bio wrote:

Dear Gromacs users,

I am doing protein in lipid-bilayer simulation and i am following the
procedure as per justin tutorial. I am able to insert the protein in
lipid bilayer and minimize the system as per Inflategro
procedure,during the total procedure the system was minimized in every
step.Then, I solvated and ionized sytem and minimized using the
following mdp file:

; minim.mdp - used as input into grompp to generate em.tpr
; Parameters describing what to do, when to stop and what to save
define = -DSTRONG_POSRES
integrator  = steep ; Algorithm (steep = steepest descent
minimization)
emtol   = 500.0 ; Stop minimization when the maximum
force < 1000.0 kJ/mol/nm
emstep  = 0.01  ; Energy step size
nsteps  = 5 ; Maximum number of (minimization)
steps to perform

; Parameters describing how to find the neighbors of each atom and how
to calculate the interactions
nstlist = 1 ; Frequency to update the neighbor
list and long range forces
ns_type = grid  ; Method to determine neighbor list
(simple, grid)
rlist   = 1.2   ; Cut-off for making neighbor list
(short range forces)
coulombtype = PME   ; Treatment of long range
electrostatic interactions
rcoulomb= 1.2   ; Short-range electrostatic cut-off
rvdw= 1.2   ; Short-range Van der Waals cut-off
pbc = xyz   ; Periodic Boundary Conditions (yes/no)

the output was as follows:

Steepest Descents converged to Fmax < 500 in 4770 steps
Potential Energy  = -3.8820288e+05
Maximum force =  4.4803549e+02 on atom 3573
Norm of force =  1.7854408e+01

As the potential energy and Fmax values were agreeable , I proceeded
to equillibrate the system using NVT.



Did you minimize the structure without restraints, prior to NVT?




  Angle   G96AngleProper Dih. Ryckaert-Bell.  Improper Dih.
2.20077e+048.54042e+036.78950e+034.34650e+033.03266e+03
  LJ-14 Coulomb-14LJ (SR)  Disper. corr.   Coulomb (SR)
4.76527e+035.50236e+048.36617e+06   -2.20019e+03   -4.46844e+05
   Coul. recip. Position Rest.  PotentialKinetic En.   Total Energy
   -1.65524e+051.07769e+017.85612e+065.88813e+105.88892e+10
  Conserved En.Temperature Pressure (bar)  Cons. rmsd ()
5.88892e+102.23805e+081.21713e+093.10245e+01



In my experience, the combination of an astronomically high temperature and a 
repulsive temperature is indicative of restraining an unrestrainable starting 
structure.  Try the EM I suggested above.  Other than that, as I've suggested 
before, see the Advanced Troubleshooting page I created in the tutorial.


-Justin


Please help me to proceed further and let me know where are the
mistakes lying and how to overcome them.

Thanks in advance,

Ram
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--


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


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Re: [gmx-users] Lipid-protein tuturial by Lemkul

2009-10-16 Thread Justin A. Lemkul



seunghwan lee wrote:

Hi

I am new to Gromacs and going through some tutorials. I am working on 
lipid-protein tutorial given by Justin Lemkul and I am stuck with the 
very first step. When I execute pdb2gmx to generate .top file and .pdb 
without hydrogen,


pdb2gmx -f KALP-15_princ.pdb -o KALP-15_processed.gro -ignh -ter -water spc

I got the following message:

---
Program pdb2gmx, VERSION 4.0.4
Source code file: pgutil.c, line: 87

Fatal error:
Atom H not found in residue 17 while adding improper

---

I made the correction to ffG53a6.rtp file as suggested by Justin, but 
apparently I am still having a problem with -NH2 residue (#17). Is there 
any other corrections I need to do in order to make this work?




No other correction is necessary.  If you fixed the .rtp file correctly, you 
should not have any problems.


-Justin


Thanks for your help!!
Seunghwan Lee


  
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--


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


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[gmx-users] Error during NVT equillibration with nvt.log file

2009-10-16 Thread ram bio
Dear Gromacs users,

I am doing protein in lipid-bilayer simulation and i am following the
procedure as per justin tutorial. I am able to insert the protein in
lipid bilayer and minimize the system as per Inflategro
procedure,during the total procedure the system was minimized in every
step.Then, I solvated and ionized sytem and minimized using the
following mdp file:

; minim.mdp - used as input into grompp to generate em.tpr
; Parameters describing what to do, when to stop and what to save
define = -DSTRONG_POSRES
integrator  = steep ; Algorithm (steep = steepest descent
minimization)
emtol   = 500.0 ; Stop minimization when the maximum
force < 1000.0 kJ/mol/nm
emstep  = 0.01  ; Energy step size
nsteps  = 5 ; Maximum number of (minimization)
steps to perform

; Parameters describing how to find the neighbors of each atom and how
to calculate the interactions
nstlist = 1 ; Frequency to update the neighbor
list and long range forces
ns_type = grid  ; Method to determine neighbor list
(simple, grid)
rlist   = 1.2   ; Cut-off for making neighbor list
(short range forces)
coulombtype = PME   ; Treatment of long range
electrostatic interactions
rcoulomb= 1.2   ; Short-range electrostatic cut-off
rvdw= 1.2   ; Short-range Van der Waals cut-off
pbc = xyz   ; Periodic Boundary Conditions (yes/no)

the output was as follows:

Steepest Descents converged to Fmax < 500 in 4770 steps
Potential Energy  = -3.8820288e+05
Maximum force =  4.4803549e+02 on atom 3573
Norm of force =  1.7854408e+01

As the potential energy and Fmax values were agreeable , I proceeded
to equillibrate the system using NVT.

The mdp file used for NVT equillibration is :

title   = NVT equilibration
define  = -DPOSRES  ; position restrain the protein
; Run parameters
integrator  = md; leap-frog integrator
nsteps  = 5 ; 2 * 5 = 100 ps
dt  = 0.002 ; 2 fs
; Output control
nstxout = 100   ; save coordinates every 0.2 ps
nstvout = 100   ; save velocities every 0.2 ps
nstenergy   = 100   ; save energies every 0.2 ps
nstlog  = 100   ; update log file every 0.2 ps
; Bond parameters
continuation= no; first dynamics run
constraint_algorithm = lincs; holonomic constraints
constraints = all-bonds ; all bonds (even heavy atom-H bonds)
constrained
lincs_iter  = 1 ; accuracy of LINCS
lincs_order = 4 ; also related to accuracy
; Neighborsearching
ns_type = grid  ; search neighboring grid cels
nstlist = 5 ; 10 fs
rlist   = 1.2   ; short-range neighborlist cutoff (in nm)
rcoulomb= 1.2   ; short-range electrostatic cutoff (in nm)
rvdw= 1.2   ; short-range van der Waals cutoff (in nm)
; Electrostatics
coulombtype = PME   ; Particle Mesh Ewald for long-range
electrostatics
pme_order   = 4 ; cubic interpolation
fourierspacing  = 0.16  ; grid spacing for FFT
; Temperature coupling is on
tcoupl  = V-rescale ; modified Berendsen thermostat
tc-grps = Protein DPPC SOL_CL-  ; three coupling groups - more accurate
tau_t   = 0.1   0.1 0.1 ; time constant, in ps
ref_t   = 323   323 323 ; reference temperature, one
for each group, in K
; Pressure coupling is off
pcoupl  = no; no pressure coupling in NVT
; Periodic boundary conditions
pbc = xyz   ; 3-D PBC
; Dispersion correction
DispCorr= EnerPres  ; account for cut-off vdW scheme
; Velocity generation
gen_vel = yes   ; assign velocities from Maxwell distribution
gen_temp= 323   ; temperature for Maxwell distribution
gen_seed= -1; generate a random seed
; COM motion removal
; These options remove motion of the protein/bilayer relative to the
solvent/ions
nstcomm = 1
comm-mode   = Linear
comm-grps   = Protein_DPPC SOL_CL-


and the output error for the mdrun is as under:

Step 0, time 0 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 0.002307, max 0.080808 (between atoms 3569 and 3570)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
starting mdrun 'Protein in DPPC in water'
5 steps,100.0 ps.

Step 0, time 0 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 31.024508, max 1431.875854 (between atoms 448 and 450)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
   453455   49.90.1331   0.2004  0.1330
   453454   50.50.1231   0.1762  0.1230
   451452   89.90.1003  29.4775  0

[gmx-users] Error during NVT equillibration

2009-10-16 Thread ram bio
Dear Gromacs users,

I am doing protein in lipid-bilayer simulation and i am following the
procedure as per justin tutorial. I am able to insert the protein in
lipid bilayer and minimize the system as per Inflategro
procedure,during the total procedure the system was minimized in every
step.Then, I solvated and ionized sytem and minimized using the
following mdp file:

; minim.mdp - used as input into grompp to generate em.tpr
; Parameters describing what to do, when to stop and what to save
define = -DSTRONG_POSRES
integrator  = steep ; Algorithm (steep = steepest descent 
minimization)
emtol   = 500.0 ; Stop minimization when the maximum force < 
1000.0 kJ/mol/nm
emstep  = 0.01  ; Energy step size
nsteps  = 5 ; Maximum number of (minimization) steps to 
perform

; Parameters describing how to find the neighbors of each atom and how
to calculate the interactions
nstlist = 1 ; Frequency to update the neighbor list and 
long range forces
ns_type = grid  ; Method to determine neighbor list (simple, 
grid)
rlist   = 1.2   ; Cut-off for making neighbor list (short range 
forces)
coulombtype = PME   ; Treatment of long range electrostatic 
interactions
rcoulomb= 1.2   ; Short-range electrostatic cut-off
rvdw= 1.2   ; Short-range Van der Waals cut-off
pbc = xyz   ; Periodic Boundary Conditions (yes/no)

the output was as follows:

Steepest Descents converged to Fmax < 500 in 4770 steps
Potential Energy  = -3.8820288e+05
Maximum force =  4.4803549e+02 on atom 3573
Norm of force =  1.7854408e+01

As the potential energy and Fmax values were agreeable , I proceeded
to equillibrate the system using NVT.

The mdp file used for NVT equillibration is :

title   = NVT equilibration
define  = -DPOSRES  ; position restrain the protein
; Run parameters
integrator  = md; leap-frog integrator
nsteps  = 5 ; 2 * 5 = 100 ps
dt  = 0.002 ; 2 fs
; Output control
nstxout = 100   ; save coordinates every 0.2 ps
nstvout = 100   ; save velocities every 0.2 ps
nstenergy   = 100   ; save energies every 0.2 ps
nstlog  = 100   ; update log file every 0.2 ps
; Bond parameters
continuation= no; first dynamics run
constraint_algorithm = lincs; holonomic constraints
constraints = all-bonds ; all bonds (even heavy atom-H bonds) 
constrained
lincs_iter  = 1 ; accuracy of LINCS
lincs_order = 4 ; also related to accuracy
; Neighborsearching
ns_type = grid  ; search neighboring grid cels
nstlist = 5 ; 10 fs
rlist   = 1.2   ; short-range neighborlist cutoff (in nm)
rcoulomb= 1.2   ; short-range electrostatic cutoff (in nm)
rvdw= 1.2   ; short-range van der Waals cutoff (in nm)
; Electrostatics
coulombtype = PME   ; Particle Mesh Ewald for long-range 
electrostatics
pme_order   = 4 ; cubic interpolation
fourierspacing  = 0.16  ; grid spacing for FFT
; Temperature coupling is on
tcoupl  = V-rescale ; modified Berendsen thermostat
tc-grps = Protein DPPC SOL_CL-  ; three coupling groups - more accurate
tau_t   = 0.1   0.1 0.1 ; time constant, in ps
ref_t   = 323   323 323 ; reference temperature, one for each 
group, in K
; Pressure coupling is off
pcoupl  = no; no pressure coupling in NVT
; Periodic boundary conditions
pbc = xyz   ; 3-D PBC
; Dispersion correction
DispCorr= EnerPres  ; account for cut-off vdW scheme
; Velocity generation
gen_vel = yes   ; assign velocities from Maxwell distribution
gen_temp= 323   ; temperature for Maxwell distribution
gen_seed= -1; generate a random seed
; COM motion removal
; These options remove motion of the protein/bilayer relative to the
solvent/ions
nstcomm = 1
comm-mode   = Linear
comm-grps   = Protein_DPPC SOL_CL-


and the output error for the mdrun is as under:

Step 0, time 0 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 0.002307, max 0.080808 (between atoms 3569 and 3570)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
starting mdrun 'Protein in DPPC in water'
5 steps,100.0 ps.

Step 0, time 0 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 31.024508, max 1431.875854 (between atoms 448 and 450)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
453455   49.90.1331   0.2004  0.1330
453454   50.50.1231   0.1762  0.1230
451452   89.90.1003  2

[gmx-users] Lipid-protein tuturial by Lemkul

2009-10-16 Thread seunghwan lee
Hi

I am new to Gromacs and going through some tutorials. I am working on 
lipid-protein tutorial given by Justin Lemkul and I am stuck with the 
very first step. When I execute pdb2gmx to generate .top file and .pdb 
without hydrogen,

pdb2gmx -f KALP-15_princ.pdb -o KALP-15_processed.gro -ignh -ter -water spc

I got the following message:

---
Program pdb2gmx, VERSION 4.0.4
Source code file: pgutil.c, line: 87

Fatal error:
Atom H not found in residue 17 while adding improper

---

I made the correction to ffG53a6.rtp file as suggested by Justin, but 
apparently I am still having a problem with -NH2 residue (#17). Is there 
any other corrections I need to do in order to make this work?

Thanks for your help!!
Seunghwan Lee


  
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Re: [gmx-users] Water molecule starting at atom X can not be settled; can't find a solution

2009-10-16 Thread Tsjerk Wassenaar
Hi Simone,

The temperature coupling might be a cause for an error like that to
occur. Try to understand that coupling ions separately may cause large
fluctuations in there velocities and hence cause sudden large
displacements that may put an ion on top of a solvent molecule that
can't be settled anymore due to that.

I assume you fixed that error, but think it's good to have a bit of
background (and please read some more) to help avoiding such mistakes
later on. If the problem persists while the T-coupling error is fixed,
then there's something else wrong :) Is it always the same water
molecule, or are they always in the neighbourhood, or does the error
occur at random water molecules? Is the water molecule close to the
edge of the box when the error occurs? Since you have all frames, you
can easily check the trajectory all the way :) You may also try
running with NVT to see whether that fixes the problem. Did you
actually equilibrate the temperature first, before putting the
pressure on? O, and you might want to show your md.mdp, as that's
where the simulation is breaking.

Hope it helps,

Tsjerk

On Fri, Oct 16, 2009 at 1:49 PM, Justin A. Lemkul  wrote:
>
>
> Simone Cirri wrote:
>>
>> Justin A. Lemkul wrote:
>>
>>    ; Berendsen temperature coupling is on in three groups
>>    Tcoupl              =  berendsen
>>
>>    tau_t = 0.1 0.1 0.1 tc-grps = protein sol NA+
>>
>>    ref_t               =  300      300     300
>>
>>    Never couple solvent and ions separately. Surely grompp warned you
>>    that you should be using "Protein Non-Protein"? See here:
>>
>>    http://www.gromacs.org/Documentation/Terminology/Thermostats
>>
>>
>> Hi Justin, thanks for the suggestion. Actually, it's an error I've always
>> been doing and I'm glad I've solved it.
>> However, I'm afraid it has nothing to do with the problem, because I just
>> tried to run the MD again (after modifying the md.mdp as you told me) and
>> the fatal error is still there.
>> I've noticed the the T-coupling mistake is also in pr.mdp. Do you think
>> that correcting it and re-running the PR simulation would fix the "water
>> molecule can not be settled" problem?
>
> It's probably worth a shot.  It's not appropriate to couple solvent and ions
> separately in any phase, equilibration or data collection.
>
> -Justin
>
>> Anyway here is the pr.mdp (as it was before):
>>
>> title               =  hsacyx
>> warnings            =  10
>> cpp                 =  /lib/cpp
>> define              =  -DPOSRES
>> constraints         =  all-bonds
>> integrator          =  md
>> dt                  =  0.002    ; ps !
>> nsteps              =  10    ; total 200.0 ps.
>> nstcomm             =  1
>> nstxout             =  250
>> nstvout             =  1000
>> nstfout             =  0
>> nstlog              =  10
>> nstenergy           =  10
>> nstlist             =  10
>> ns_type             =  grid
>> rlist               =  0.9
>> coulombtype        =  PME
>> rcoulomb            =  0.9
>> rvdw                =  0.9
>> fourierspacing        =  0.12
>> fourier_nx        =  0
>> fourier_ny        =  0
>> fourier_nz        =  0
>> pme_order        =  6
>> ewald_rtol        =  1e-5
>> optimize_fft        =  yes
>> ; Berendsen temperature coupling is on in four  groups
>> Tcoupl              =  berendsen
>> tau_t               =  0.1     0.1    0.1
>> tc-grps            =  Protein     SOL    NA+
>> ref_t               =  300     300    300
>> ; Pressure coupling is on
>> Pcoupl              =  berendsen
>> pcoupltype          =  isotropic
>> tau_p               =  0.5
>> compressibility     =  4.5e-5
>> ref_p               =  1.0
>> ; Generate velocites is on at 300 K.
>> gen_vel             =  yes
>> gen_temp            =  300.0
>> gen_seed            =  173529
>>
>> Thank you
>>
>> Simone Cirri
>>
>>
>> 
>>
>> ___
>> gmx-users mailing list    gmx-us...@gromacs.org
>> http://lists.gromacs.org/mailman/listinfo/gmx-users
>> Please search the archive at http://www.gromacs.org/search before posting!
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>
> --
> 
>
> Justin A. Lemkul
> Ph.D. Candidate
> ICTAS Doctoral Scholar
> 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    gmx-us...@gromacs.org
> http://lists.gromacs.org/mailman/listinfo/gmx-users
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> Can'

Re: [gmx-users] Water molecule starting at atom X can not be settled; can't find a solution

2009-10-16 Thread Justin A. Lemkul



Simone Cirri wrote:

Justin A. Lemkul wrote:

; Berendsen temperature coupling is on in three groups
Tcoupl  =  berendsen

tau_t = 0.1 0.1 0.1 tc-grps = protein sol NA+

ref_t   =  300  300 300

Never couple solvent and ions separately. Surely grompp warned you
that you should be using "Protein Non-Protein"? See here:

http://www.gromacs.org/Documentation/Terminology/Thermostats


Hi Justin, thanks for the suggestion. Actually, it's an error I've 
always been doing and I'm glad I've solved it.
However, I'm afraid it has nothing to do with the problem, because I 
just tried to run the MD again (after modifying the md.mdp as you told 
me) and the fatal error is still there.
I've noticed the the T-coupling mistake is also in pr.mdp. Do you think 
that correcting it and re-running the PR simulation would fix the "water 
molecule can not be settled" problem?


It's probably worth a shot.  It's not appropriate to couple solvent and ions 
separately in any phase, equilibration or data collection.


-Justin


Anyway here is the pr.mdp (as it was before):

title   =  hsacyx
warnings=  10
cpp =  /lib/cpp
define  =  -DPOSRES
constraints =  all-bonds
integrator  =  md
dt  =  0.002; ps !
nsteps  =  10; total 200.0 ps.
nstcomm =  1
nstxout =  250
nstvout =  1000
nstfout =  0
nstlog  =  10
nstenergy   =  10
nstlist =  10
ns_type =  grid
rlist   =  0.9
coulombtype=  PME
rcoulomb=  0.9
rvdw=  0.9
fourierspacing=  0.12
fourier_nx=  0
fourier_ny=  0
fourier_nz=  0
pme_order=  6
ewald_rtol=  1e-5
optimize_fft=  yes
; Berendsen temperature coupling is on in four  groups
Tcoupl  =  berendsen
tau_t   =  0.1 0.10.1
tc-grps=  Protein SOLNA+
ref_t   =  300 300300
; Pressure coupling is on
Pcoupl  =  berendsen
pcoupltype  =  isotropic
tau_p   =  0.5
compressibility =  4.5e-5
ref_p   =  1.0
; Generate velocites is on at 300 K.
gen_vel =  yes
gen_temp=  300.0
gen_seed=  173529

Thank you

Simone Cirri




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--


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


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Re: [gmx-users] question about all atoms lipid molecule

2009-10-16 Thread Pär Bjelkmar

Hi,

I need to do an all atom simulation for dppc bilayer . You are right  
the

dppc molecule file that i have has PALM and PCGL residues.
Well, I don't know where you got the dppc molecule from, I thought you  
said you didn't have any DPPC structure with hydrogens? Anyway, I'll  
send you the current version of the charmm force field for GROMACS (in  
a separate e-mail) but I'm afraid I cannot help you in building the  
residue. I think it might be quite a lot of work if you don't know how  
CHARMM is doing it. My suggestion is that you search/ask the CHARMM  
mailing list for how DPPC is constructed.


I will like to try to set up the charmm FF for gromacs. But I dont  
have the

FF files with me, neither do i have the programs. Could you send me a
tutorial or some reference link too ( if you know of any).
What you need for running CHARMM ff in GROMACS are the files I'll send  
you and the latest version of the source code (i.e. do a git pull and  
recompile).


/Pär___
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Re: [gmx-users] Water molecule starting at atom X can not be settled; can't find a solution

2009-10-16 Thread Simone Cirri
Justin A. Lemkul wrote:

; Berendsen temperature coupling is on in three groups
> Tcoupl  =  berendsen
>
> tau_t = 0.1 0.1 0.1 tc-grps = protein sol NA+
>
> ref_t   =  300  300 300
>
> Never couple solvent and ions separately. Surely grompp warned you that you
> should be using "Protein Non-Protein"? See here:
>
> http://www.gromacs.org/Documentation/Terminology/Thermostats
>
>
Hi Justin, thanks for the suggestion. Actually, it's an error I've always
been doing and I'm glad I've solved it.
However, I'm afraid it has nothing to do with the problem, because I just
tried to run the MD again (after modifying the md.mdp as you told me) and
the fatal error is still there.
I've noticed the the T-coupling mistake is also in pr.mdp. Do you think that
correcting it and re-running the PR simulation would fix the "water molecule
can not be settled" problem?
Anyway here is the pr.mdp (as it was before):

title   =  hsacyx
warnings=  10
cpp =  /lib/cpp
define  =  -DPOSRES
constraints =  all-bonds
integrator  =  md
dt  =  0.002; ps !
nsteps  =  10; total 200.0 ps.
nstcomm =  1
nstxout =  250
nstvout =  1000
nstfout =  0
nstlog  =  10
nstenergy   =  10
nstlist =  10
ns_type =  grid
rlist   =  0.9
coulombtype=  PME
rcoulomb=  0.9
rvdw=  0.9
fourierspacing=  0.12
fourier_nx=  0
fourier_ny=  0
fourier_nz=  0
pme_order=  6
ewald_rtol=  1e-5
optimize_fft=  yes
; Berendsen temperature coupling is on in four  groups
Tcoupl  =  berendsen
tau_t   =  0.1 0.10.1
tc-grps=  Protein SOLNA+
ref_t   =  300 300300
; Pressure coupling is on
Pcoupl  =  berendsen
pcoupltype  =  isotropic
tau_p   =  0.5
compressibility =  4.5e-5
ref_p   =  1.0
; Generate velocites is on at 300 K.
gen_vel =  yes
gen_temp=  300.0
gen_seed=  173529

Thank you

Simone Cirri
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Re: [gmx-users] Water molecule starting at atom X can not be settled; can't find a solution

2009-10-16 Thread Justin A. Lemkul



Simone Cirri wrote:




; Berendsen temperature coupling is on in three groups
Tcoupl  =  berendsen
tau_t   =  0.1  0.1  0.1
tc-grps=  protein  sol NA+

ref_t   =  300  300 300


Never couple solvent and ions separately.  Surely grompp warned you that you 
should be using "Protein Non-Protein"?  See here:


http://www.gromacs.org/Documentation/Terminology/Thermostats

-Justin

--


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


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[gmx-users] Water molecule starting at atom X can not be settled; can't find a solution

2009-10-16 Thread Simone Cirri
Hi everyone,

in the last weeks I've been trying to run a simulation with Gromacs 4.0.5
and the force field ffamber99.
The protein is albumine (BSA, bovine serum albumine), so it's a very big one
(570+ residues).
The solvent is tip3p.
After an energy minimization run and a position restraint run, I start with
the "real" simulation. Invariably, it crashes after 1 ps with the error
message:

t = 1.000 ps: Water molecule starting at atom 42031 can not be settled.
Check for bad contacts and/or reduce the timestep.

I've searched in the mailing list and I've tried many of the solutions you
proposed:

- I looked at the water molecule with the problematic atom to see if it was
interacting in some weird way with the protein (I put ntsxout = 1 in order
to have many more frames); but it isn't so, since that molecule is only one
of the many solvent molecules that (at least in the first ps) stay far from
the protein
- I tried to run a longer and stronger minimization: so I increased the
number of steps (from 1 to 2) and I decreased emtol (from 100 to 1),
but nothing changed
- I tried to increase the box dimensions; in editconf I put -c 1.2 (instead
of 0.7), but nothing changed.
- I checked the stepXXXb.pdb and stepXXXc.pdb that mdrun created after the
crash, but I didn't see anything strange in them.
- I did a longer position restraint run (3 ns instead of the usual 200 ps)
but nothing changed... I was hoping that it would stabilize the water, but I
think the problem is not that.

Even though the energy minimization doesn't show any problems, I think
that's the crucial part; as someone said in another message, the problem
doesn't really involve the water molecule that cannot be settled, but other
atoms in the protein with big forces that in some way collide with the water
molecule... am I right?
In this case, deleting the problematic water molecule could help? I thought
it would be useless, since that molecule is not close to the protein at
all...

Here you have the em.mdp and the md.mdp, if you want I can also paste the
pr.mdp .

title   =  hsacyx
cpp =  /lib/cpp
define  =  -DFLEX_SPC
constraints =  none
integrator  =  steep
dt  =  0.002; ps !
nsteps  =  2
nstlist =  10
ns_type =  grid
rlist   =  0.9
coulombtype=  PME
rcoulomb=  0.9
rvdw=  0.9
fourierspacing=  0.12
fourier_nx=  0
fourier_ny=  0
fourier_nz=  0
pme_order=  6
ewald_rtol=  1e-5
optimize_fft=  yes
;
;   Energy minimizing stuff
;
emtol   =  1
emstep  =  0.01



title   =  hsacyx
cpp =  /lib/cpp
constraints =  all-bonds
integrator  =  md
dt  =  0.002; ps !
nsteps  =  750; total 15000 ps.
nstcomm =  1
nstxout =  2500
nstvout =  0
nstfout =  0
nstlist =  500
ns_type =  grid
rlist   =  0.9
coulombtype=  PME
rcoulomb=  0.9
rvdw=  0.9
fourierspacing=  0.12
fourier_nx=  0
fourier_ny=  0
fourier_nz=  0
pme_order=  6
ewald_rtol=  1e-5
optimize_fft=  yes
; Berendsen temperature coupling is on in three groups
Tcoupl  =  berendsen
tau_t   =  0.1  0.1  0.1
tc-grps=  protein  sol NA+
ref_t   =  300  300 300
; Pressure coupling is on
Pcoupl  =  berendsen
pcoupltype  =  isotropic
tau_p   =  0.5
compressibility =  4.5e-5
ref_p   =  1.0
; Generate velocites is on at 300 K.
gen_vel =  yes
gen_temp=  300.0
gen_seed=  173529


I really don't know what else I could do... if someone has an idea, I would
be glad to hear it.
Thank you

Simone Cirri
PhD student at the Structural Biology Lab of University of Siena, Italy
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[gmx-users] Coarse-Grain: GROMACS bond information to VMD

2009-10-16 Thread Thomas Schmidt
Dear all,

is there any possibility to give the bond information out of GROMACS
files to VMD? Especially for coarse-grained models (using the MARTINI
FF) this would be a nice feature for visualization.

But in that case the distance analysis doesn't work, because we will
always have too high distances between two particles (CG scale). If I
use "Dynamic Bonds" (as described in this thread:
http://oldwww.gromacs.org/pipermail/gmx-users/2008-September/036124.html) VMD 
draws bonds also between non-bonded particles.

I know that there is no official solutions for this
(http://www.gromacs.org/Developer_Zone/Programming_Guide/VMD), but maybe
anybody of you has a script to convert *.top/*.itp/*.rtp files with a
corresponding *.gro file into the PDB format with connectivity section
or into the (NAMD) *.psf format. (?)
The solution that I've found (top2psd.pl) is not smart enough because
it's a simple 1-to-1 conversion of GROMACS topology files and has not
the ability to replicate (and renumber) the topological data of single
molecules (http://baaden.free.fr/soft/compchem.html).

Thanks for your help...
Thomas

-- 
Thomas H. Schmidt, PhD student
Computational Structural Biology
Chair of Life Science Informatics, B-IT
LIMES-Institute, University of Bonn
Dahlmannstrasse 2, D-53113 Bonn, Germany

Phone: +49-(0)228-2699 323
Fax: +49-(0)228-2699 341
http://www.csb.bit.uni-bonn.de


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Re: [gmx-users] LAM OpenMPI conflict?

2009-10-16 Thread Francesco Pietra
For your information, the procedure is:

$ grompp ... (to generate minimize.tpr)

$ lamboot

$ l$ mdrun_mpi -np 4 -v -s minimize.tpr -o mod21_traj.trr -c mod21.gro
-e mod21_ener.edr

It worked nicely, exactly as the serial run "mdrun -v -s minimize.tpr ...".
No interference with installed openmpi, no need to mention lam in the
md command line. Forget about the Debian compilation, it does not
require any special command.

Have a nice day

francesco

On Thu, Oct 15, 2009 at 7:55 PM, Jussi Lehtola
 wrote:
> On Thu, 2009-10-15 at 18:23 +0200, Francesco Pietra wrote:
>> Hi: I was trying to minimize in vacuum a pure CG protein on a four
>> core (two dual operons), getting errors:
>>
>> $ lamboot
>>
>> $ mpirun -np 4 mdrun -s mod21.tpr -o minim_mod21_traj.trr -c
>> minim_mod21.gro -e minim_mod21_ener.edr
>> ...
>> ...
>>
>> WARNING: Writing ompirun noticed that job rank 2 with PID 4385 on node
>> tya64 exited on signal 11 (Segmentation fault).
>> 3 processes killed (possibly by Open MPI)
>> Writing out atom name (SCSP1) longer than 4 characters to .pdb file
>
> This looks like you are trying to run the LAM binary with Open MPI's
> mpirun command. Use the LAM version instead (mpirun.lam in Debian).
>
> Furthermore, the Debian packages use suffixes, for instance the binaries
> in the gromacs-lam package are /usr/bin/mdrun_mpi.lam
> and /usr/bin/mdrun_mpi_d.lam, so you should switch mdrun to
> mdrun_mpi.lam . So all in all:
>
> $ mpirun.lam -np 4 mdrun_mpi.lam -s mod21.tpr -o minim_mod21_traj.trr -c
> minim_mod21.gro -e minim_mod21_ener.edr
>
> What is also possible is that your installation of the Intel compiled
> Open MPI is visible in your environment, which may quite well lead into
> problems.
>
> (Also, LAM has been obsoleted by Open MPI years ago, so you might just
> try switching from LAM to Open MPI, then you wouldn't have to run
> lamboot at the beginning.)
> --
> --
> Jussi Lehtola, FM, Tohtorikoulutettava
> Fysiikan laitos, Helsingin Yliopisto
> jussi.leht...@helsinki.fi, p. 191 50632
> --
> Mr. Jussi Lehtola, M. Sc., Doctoral Student
> Department of Physics, University of Helsinki, Finland
> jussi.leht...@helsinki.fi
> --
>
>
> ___
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RE: [gmx-users] a bit strange errors

2009-10-16 Thread wuxiao

Dear Berk,

In fact, I calculated the potential and force from the analytical function of 
angles in degrees, which is multicentred Gaussian-based potentials. So I think 
it must be some other reasons that cause the issues. Anyway, thanks again for 
your reply.

Best wishes,
Chaofu Wu, Dr.


From: g...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 09:39:07 +0200



Hi,

But there could be a very similar issue there for the conversion from radians 
to degrees.
The force has to be in units of kJ/mol/degree, not kJ/mol/radian.

Berk



From: xiaowu...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 15:35:19 +0800



Dear Berk,
   Unfortunately, this time it is angle (table_a0.xvg) that cause the problem. 
The angles are taken in degrees. I think it is not due to the wrong unit. 
Anyway, thanks very much for your reply.
 Best wishes,
Chaofu Wu, Dr.


From: g...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 09:21:18 +0200



Hi,

Last week another user reported very similar problems (also 164% deviations, I 
think).
In that case it seemed that the user did an Angstrom to nm conversion in the 
table file
on x without scaling f(x). Could this also be your issue?

Berk



From: xiaowu...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 14:55:40 +0800



Dear Mark,
   Thank you very much for the quick reply to my post. According to your 
suggestion, I check the table and reformat it with equal spacing between 
entries. I also check the entries calculated from the analytical functions and 
no wrong values are found. However, the same warnings are given, which lead to 
terminate the simulation. Are there any other reasons responsible for it?
Best wishes,
Chaofu Wu, Dr. 
> Date: Fri, 16 Oct 2009 14:18:17 +1100
> From: mark.abra...@anu.edu.au
> To: gmx-users@gromacs.org
> Subject: Re: [gmx-users] a bit strange errors
> 
> wuxiao wrote:
> > Dear GMXers,
> > Recently, I has been performing coarse-grained MD simulations based 
> > on the tabulated potentials using GROMACS. In the initialization, some 
> > warnings are given as follows 
> > /WARNING: For the 999 non-zero entries for table 0 in table_b0.xvg the 
> > forces deviate on average 164% from minus the numerical derivative of 
> > the potential/
> 
> This looks like your table has either wrong values or wrong formatting.
> It does have to have equal spacing between entries.
> 
> > It proceeds untill at about 17 ns before it is interupted with some errors
> > /WARNING: 1-4 interaction between 148 and 151 at distance 13.125 which > > 
> > is larger than the 1-4 table size 2.000 nm/
> > I think the duartion time is long enough to equilibrated the system, 
> > which is confirmed by the energy plot with time. Why it happens so? What 
> > should I do to cope with this problem? Thanks a lot for any reply to 
> 
> Perhaps much of the table is fine, and the problem only arises when you
> get a force being looked up in an erroneous part.
> 
> Mark
> ___
> gmx-users mailing list gmx-users@gromacs.org
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RE: [gmx-users] a bit strange errors

2009-10-16 Thread Berk Hess

Hi,

But there could be a very similar issue there for the conversion from radians 
to degrees.
The force has to be in units of kJ/mol/degree, not kJ/mol/radian.

Berk

From: xiaowu...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 15:35:19 +0800








Dear Berk,

   Unfortunately, this time it is angle (table_a0.xvg) that cause the problem. 
The angles are taken in degrees. I think it is not due to the wrong unit. 
Anyway, thanks very much for your reply.
 Best wishes,

Chaofu Wu, Dr.


From: g...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 09:21:18 +0200



Hi,

Last week another user reported very similar problems (also 164% deviations, I 
think).
In that case it seemed that the user did an Angstrom to nm conversion in the 
table file
on x without scaling f(x). Could this also be your issue?

Berk



From: xiaowu...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 14:55:40 +0800



Dear Mark,
   Thank you very much for the quick reply to my post. According to your 
suggestion, I check the table and reformat it with equal spacing between 
entries. I also check the entries calculated from the analytical functions and 
no wrong values are found. However, the same warnings are given, which lead to 
terminate the simulation. Are there any other reasons responsible for it?
Best wishes,
Chaofu Wu, Dr. 
> Date: Fri, 16 Oct 2009 14:18:17 +1100
> From: mark.abra...@anu.edu.au
> To: gmx-users@gromacs.org
> Subject: Re: [gmx-users] a bit strange errors
> 
> wuxiao wrote:
> > Dear GMXers,
> > Recently, I has been performing coarse-grained MD simulations based 
> > on the tabulated potentials using GROMACS. In the initialization, some 
> > warnings are given as follows 
> > /WARNING: For the 999 non-zero entries for table 0 in table_b0.xvg the 
> > 
 forces deviate on average 164% from minus the numerical derivative of 
> > the potential/
> 
> This looks like your table has either wrong values or wrong formatting.
> It does have to have equal spacing between entries.
> 
> > It proceeds untill at about 17 ns before it is interupted with some errors
> > /WARNING: 1-4 interaction between 148 and 151 at distance 13.125 which > > 
> > is larger than the 1-4 table size 2.000 nm/
> > I think the duartion time is long enough to equilibrated the system, 
> > which is confirmed by the energy plot with time. Why it happens so? What 
> > should I do to cope with this problem? Thanks a lot for any reply to 
> 
> Perhaps much of the table is fine, and the problem only arises when you
> get a force being looked up in an erroneous part.
> 
> Mark
> ___
> gmx-users mailing
  list gmx-users@gromacs.org
> http://lists.gromacs.org/mailman/listinfo/gmx-users
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RE: [gmx-users] a bit strange errors

2009-10-16 Thread wuxiao

Dear Berk,

   Unfortunately, this time it is angle (table_a0.xvg) that cause the problem. 
The angles are taken in degrees. I think it is not due to the wrong unit. 
Anyway, thanks very much for your reply.
 Best wishes,

Chaofu Wu, Dr.


From: g...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 09:21:18 +0200



Hi,

Last week another user reported very similar problems (also 164% deviations, I 
think).
In that case it seemed that the user did an Angstrom to nm conversion in the 
table file
on x without scaling f(x). Could this also be your issue?

Berk



From: xiaowu...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 14:55:40 +0800



Dear Mark,
   Thank you very much for the quick reply to my post. According to your 
suggestion, I check the table and reformat it with equal spacing between 
entries. I also check the entries calculated from the analytical functions and 
no wrong values are found. However, the same warnings are given, which lead to 
terminate the simulation. Are there any other reasons responsible for it?
Best wishes,
Chaofu Wu, Dr. 
> Date: Fri, 16 Oct 2009 14:18:17 +1100
> From: mark.abra...@anu.edu.au
> To: gmx-users@gromacs.org
> Subject: Re: [gmx-users] a bit strange errors
> 
> wuxiao wrote:
> > Dear GMXers,
> > Recently, I has been performing coarse-grained MD simulations based 
> > on the tabulated potentials using GROMACS. In the initialization, some 
> > warnings are given as follows 
> > /WARNING: For the 999 non-zero entries for table 0 in table_b0.xvg the 
> > forces deviate on average 164% from minus the numerical derivative of 
> > the potential/
> 
> This looks like your table has either wrong values or wrong formatting.
> It does have to have equal spacing between entries.
> 
> > It proceeds untill at about 17 ns before it is interupted with some errors
> > /WARNING: 1-4 interaction between 148 and 151 at distance 13.125 which > > 
> > is larger than the 1-4 table size 2.000 nm/
> > I think the duartion time is long enough to equilibrated the system, 
> > which is confirmed by the energy plot with time. Why it happens so? What 
> > should I do to cope with this problem? Thanks a lot for any reply to 
> 
> Perhaps much of the table is fine, and the problem only arises when you
> get a force being looked up in an erroneous part.
> 
> Mark
> ___
> gmx-users mailing list gmx-users@gromacs.org
> http://lists.gromacs.org/mailman/listinfo/gmx-users
> Please search the archive at http://www.gromacs.org/search before posting!
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RE: [gmx-users] a bit strange errors

2009-10-16 Thread Berk Hess

Hi,

Last week another user reported very similar problems (also 164% deviations, I 
think).
In that case it seemed that the user did an Angstrom to nm conversion in the 
table file
on x without scaling f(x). Could this also be your issue?

Berk

From: xiaowu...@hotmail.com
To: gmx-users@gromacs.org
Subject: RE: [gmx-users] a bit strange errors
Date: Fri, 16 Oct 2009 14:55:40 +0800








Dear Mark,

   Thank you very much for the quick reply to my post. According to your 
suggestion, I check the table and reformat it with equal spacing between 
entries. I also check the entries calculated from the analytical functions and 
no wrong values are found. However, the same warnings are given, which lead to 
terminate the simulation. Are there any other reasons responsible for it?

Best wishes,

Chaofu Wu, Dr. 
> Date: Fri, 16 Oct 2009 14:18:17 +1100
> From: mark.abra...@anu.edu.au
> To: gmx-users@gromacs.org
> Subject: Re: [gmx-users] a bit strange errors
> 
> wuxiao wrote:
> > Dear GMXers,
> > Recently, I has been performing coarse-grained MD simulations based 
> > on the tabulated potentials using GROMACS. In the initialization, some 
> > warnings are given as follows 
> > /WARNING: For the 999 non-zero entries for table 0 in table_b0.xvg the 
> > forces deviate on average 164% from minus the numerical derivative of 
> > the potential/
> 
> This looks like your table has either wrong values or wrong formatting.
> It does have to have equal spacing between entries.
> 
> > It proceeds untill at about 17 ns before it is interupted with some errors
> > /WARNING: 1-4 interaction between 148 and 151 at distance 13.125 which > > 
> > is larger than the 1-4 table size 2.000 nm/
> > I think the duartion time is long enough to equilibrated the system, 
> > which is confirmed by the energy plot with time. Why it happens so? What 
> > should I do to cope with this problem? Thanks a lot for any reply to 
> 
> Perhaps much of the table is fine, and the problem only arises when you
> get a force being looked up in an erroneous part.
> 
> Mark
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