Re: [gmx-users] Problem with trjconv and centering bilayer.

2012-01-16 Thread Justin A. Lemkul



Ioannis Beis wrote:

Dear gromacs users,

I am trying to center the trajectory of a bilayer in the rectangular 
simulation box in the frame of my effort to calculate the bilayer 
thickness with g_dist. According to the visualization, the upper layer 
of the membrane lies on the lowest part of the box and the lower part of 
the membrane on the highest part of the box, with the water in the 
middle. There should not be anything wrong with drifting along the 
z-axis, since the initial structure was at the very bottom of the box, 
so even a small drift downwards -due to the pbc- would place the lower 
part of the membrane on the top of the box.


I tried issuing:

trjconv -f my_trajectory.xtc -s my_initial_structure.gro -o 
my_trajectory_no_jump.xtc -pbc nojump


with 0 (for system) and subsequently

trjconv -f my_trajectory_no_jump.xtc -s DOPC_1DOG.tpr -o 
my_trajectory_no_jump_center.xtc -center -boxcenter tric -pbc mol


with 1 (other) for centering and 0 (system) for output.

I used this kind of commands some time ago and they worked fine. Now 
strangely the bilayer remains around the position that I described in 
the beginning. Is it possible that the program treats the bilayer 
separated as it looks in vmd and considers the geometrical center in the 
middle of the water instead of the middle of the bilayer?




That's exactly what it does.

I tried the -trans flag to translate the bilayer along z-axis near the 
center and repeated the steps, but the new trajectory wasn't even 
visible in vmd. In addition, the .gro files generated by trjconv are 
apparently trajectory files instead of structure files. I don't feel 
confident about using editconf for operations like translation of a 
single initial structure, because as far as I understand editconf is a 
tool meant mostly for setting up systems; thus I was sceptical about 
messing a structure with editconf that I would later on use together 
with an .xtc file as input for trjconv.  However, trjconv doesn't seem 
to generate structure output files. I don't understand the meaning of a 
.gro file as trajectory file since there are already at least 3 file 
formats for trajectories.




Generally speaking, a trajectory is just a series of coordinates, so you can 
output it into a number of formats, including .gro and .pdb, among others.  You 
get a chain of coordinate files that may (or may not) end up being useful in 
some applications.


So how can I bring my bilayer's trajectory in the center of the unit 
cell for reliable thickness calculation without drifts? Is it possible 
at the same time to have clear visualization without disturbances? 
trjconv with -pbc mol still gives rise to lines in the visualization, 
apparently as a result of atom jumps. Sadly trajectory files cannot be 
inspected and visualization is quite handy for certain types of feedback 
in various data analysis-related tasks, so it would be nice if the 
trajectories used for analysis also look proper in vmd.




I can think of two approaches, the first of which I have used so it should work 
;)

1. Provide a custom index group specifying only a single lipid atom from the end 
of a hydrocarbon chain and center on it.  Therefore, its geometric center has to 
be the center of the box, and it should bring the rest of the membrane to the 
(visual) center of the unit cell.


2. Calculate the distance with the trajectory you have now, and subtract it from 
the z-length (assuming the membrane plane is x-y) of the box (stored in the .edr 
file).


-Justin

--


Justin A. Lemkul
Ph.D. Candidate
ICTAS Doctoral Scholar
MILES-IGERT Trainee
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] Problem with trjconv and centering bilayer.

2012-01-16 Thread Ioannis Beis

Dear gromacs users,

I am trying to center the trajectory of a bilayer in the rectangular  
simulation box in the frame of my effort to calculate the bilayer  
thickness with g_dist. According to the visualization, the upper layer  
of the membrane lies on the lowest part of the box and the lower part  
of the membrane on the highest part of the box, with the water in the  
middle. There should not be anything wrong with drifting along the  
z-axis, since the initial structure was at the very bottom of the box,  
so even a small drift downwards -due to the pbc- would place the lower  
part of the membrane on the top of the box.


I tried issuing:

trjconv -f my_trajectory.xtc -s my_initial_structure.gro -o  
my_trajectory_no_jump.xtc -pbc nojump


with 0 (for system) and subsequently

trjconv -f my_trajectory_no_jump.xtc -s DOPC_1DOG.tpr -o  
my_trajectory_no_jump_center.xtc -center -boxcenter tric -pbc mol


with 1 (other) for centering and 0 (system) for output.

I used this kind of commands some time ago and they worked fine. Now  
strangely the bilayer remains around the position that I described in  
the beginning. Is it possible that the program treats the bilayer  
separated as it looks in vmd and considers the geometrical center in  
the middle of the water instead of the middle of the bilayer?


I tried the -trans flag to translate the bilayer along z-axis near the  
center and repeated the steps, but the new trajectory wasn't even  
visible in vmd. In addition, the .gro files generated by trjconv are  
apparently trajectory files instead of structure files. I don't feel  
confident about using editconf for operations like translation of a  
single initial structure, because as far as I understand editconf is a  
tool meant mostly for setting up systems; thus I was sceptical about  
messing a structure with editconf that I would later on use together  
with an .xtc file as input for trjconv.  However, trjconv doesn't seem  
to generate structure output files. I don't understand the meaning of  
a .gro file as trajectory file since there are already at least 3 file  
formats for trajectories.


So how can I bring my bilayer's trajectory in the center of the unit  
cell for reliable thickness calculation without drifts? Is it possible  
at the same time to have clear visualization without disturbances?  
trjconv with -pbc mol still gives rise to lines in the visualization,  
apparently as a result of atom jumps. Sadly trajectory files cannot be  
inspected and visualization is quite handy for certain types of  
feedback in various data analysis-related tasks, so it would be nice  
if the trajectories used for analysis also look proper in vmd.


Thank you in advance.

Best regards,
Ioannis


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[gmx-users] problem with trjconv -pbc cluster

2010-07-07 Thread chris . neale
I wrote my own program to do this and so I never tried that one. We  
did find that clustering based on a dingle atom in the chain was a  
very good idea. So take your distal carbon in the surfactant and make  
in index group of it and cluster it (with a larger cutoff) with  
g_clustsize.


Obviously if there is a problem with g_clustsize then you should also  
file a bugzilla.


If you're going to continue with this thread about g_clustsize, then  
please pick an appropriate subject line so that others can search it  
usefully later.


Chris.

-- original message --

Hi Chris,  Thanks a lot for your responses. I will surely try them.  
But, before I go to trjconv -pbc cluster, I had one more problem to  
sort out. This has to do with quantifying the cluster-size  
distribution from the trajectory. As I mentioned, if I visualize the  
trajectory in VMD, I see that starting from a random dispersed state  
of 50 molecules of surfactant, it aggregates gradually and at a long  
time, two distinct miceller aggregates are formed.But, If I try to  
quantify the cluster-size distribution using g_clustsize utilty, it  
gives me bizarre results: the maxclust.xvg for the final time frame  
shows that I have 1 single cluster containing all the 50 molecules.  
But, Vmd shows 2 distinct aggregate.
Here is the command line I used:   g_clustsize -f traj.xtc -s topol  
-mol -cut 0.50 I used -mol option so that I get the cluster size  
distribution in terms of the molecules.Here, executing the commands  
gives me maxclust.xvg which has maximum size of clusters( in terms of  
molecule number) as a function of time frame. It shows at the end,  
maxclustersize  is 50 and it has all the particles in it( as obtained  
from maxclust.ndx)Besides, at any other time, the maximum size of  
particles predicted by g_clustsize does not match with what VMD shows.  
I also  tried post-processing the trajectory using trjconv with -pbc  
whole or with -pbc nojump . But, g_clustsize always returns same  
result:maxcluster contains all the particles.Then I tried playing with  
-cut option : I started with default value of 0.35, here the result is  
worse: it shows maxclust = 1 i.e all the particles are monomeric . But  
any value beyond 0.35 gives me maxclust = 50.   I tried to
 cross-check whether visualization is misrepresented or not: for this  
I tried to calculate all the distances among the com of the  
surfectants using g_dist tool and tried to manually cluster the  
surfectants and I found that here I can easily come up with two  
separate cluster based on the distances. So, I think that the problem  
lies in g_clustsize not in visualization, as -pbc whole or -pbc nojump  
does not change the result.So, do you have any suggestions ? Any help  
in pointing out where I am doing wrong will be helpful.Jagannath


--- On Wed, 7/7/10, chris.neale at utoronto.ca utoronto.ca> wrote:


From: chris.neale at utoronto.ca 
Subject: [gmx-users] problem with trjconv -pbc cluster
To: gmx-users at gromacs.org
Date: Wednesday, 7 July, 2010, 9:27 PM


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Re: [gmx-users] problem with trjconv -pbc cluster

2010-07-07 Thread jagannath mondal
Hi Chris,  Thanks a lot for your responses. I will surely try them. But, before 
I go to trjconv -pbc cluster, I had one more problem to sort out. This has to 
do with quantifying the cluster-size distribution from the trajectory. As I 
mentioned, if I visualize the trajectory in VMD, I see that starting from a 
random dispersed state of 50 molecules of surfactant, it aggregates gradually 
and at a long time, two distinct miceller aggregates are formed.But, If I try 
to quantify the cluster-size distribution using g_clustsize utilty, it gives me 
bizarre results: the maxclust.xvg for the final time frame shows that I have 1 
single cluster containing all the 50 molecules. But, Vmd shows 2 distinct 
aggregate.
Here is the command line I used:   g_clustsize -f traj.xtc -s topol -mol -cut 
0.50 I used -mol option so that I get the cluster size distribution in terms of 
the molecules.Here, executing the commands gives me maxclust.xvg which has 
maximum size of clusters( in terms of molecule number) as a function of time 
frame. It shows at the end, maxclustersize  is 50 and it has all the particles 
in it( as obtained from maxclust.ndx)Besides, at any other time, the maximum 
size of particles predicted by g_clustsize does not match with what VMD 
shows. I also  tried post-processing the trajectory using trjconv with -pbc 
whole or with -pbc nojump . But, g_clustsize always returns same 
result:maxcluster contains all the particles.Then I tried playing with -cut 
option : I started with default value of 0.35, here the result is worse: it 
shows maxclust = 1 i.e all the particles are monomeric . But any value beyond 
0.35 gives me maxclust = 50.   I tried to
 cross-check whether visualization is misrepresented or not: for this I tried 
to calculate all the distances among the com of the surfectants using g_dist 
tool and tried to manually cluster the surfectants and I found that here I can 
easily come up with two separate cluster based on the distances. So, I think 
that the problem lies in g_clustsize not in visualization, as -pbc whole or 
-pbc nojump does not change the result.So, do you have any suggestions ? Any 
help in pointing out where I am doing wrong will be helpful.Jagannath

--- On Wed, 7/7/10, chris.ne...@utoronto.ca  wrote:

From: chris.ne...@utoronto.ca 
Subject: [gmx-users] problem with trjconv -pbc cluster
To: gmx-users@gromacs.org
Date: Wednesday, 7 July, 2010, 9:27 PM

PS:

you realize that trjconv -pbc cluster is never going to work unless you 
actually have a cluster, right? So you can't start this procedure near your 
initial dispersed state. You need to start at some time T where you actually do 
have a cluster. Then you can try -dump T, -dump (T+X), -dump (T+X*2), etc. Then 
you can follow the ides expressed below like running backwards with -pbc nojup 
to get the initial state.

Chris.

--original message --

Dear Jagannath:

There is, as far as I know, no way to fix this. Here's what you should do.

1. Let the space between your timesteps be X ps.
2. Use trjconv -pbc cluster -dump X -o out.gro
2b. if that doesn't work, try trjconv -pbc cluster -dump (X*2) -o out.gro
2c. if that doesn't work, try trjconv -pbc cluster -dump (X*3) -o out.gro
...
(Note use real numbers for args to -dump).

Once you have a frame that works, you can run part 2 and 3 of that
wiki page by making a tpr based on the gro that worked -- and I think
that you'll need to run your trjconv -pbc mol starting from the frame
where clustering worked (e.g. -b X). Note that this second requirement
means that you may need to reverse the frames from your .xtc file so
that you can run in reverse time from a complete micelle through to
disassembly with -pbc nojump -- a for loop around trjconv will work
but inefficiently, you might be able to use -demux smartly here (I'm
not sure).

But then since you have 2 micelles you will need a starting box in
which they are both whole getting trickier. You should be aware
that the trjconv -pbc cluster is not the only way to do part 1 from
that wiki page. You could use trjconv -trans X Y Z and then make a new
.tpr and then run trjconv -pbc nojump and it would work if only you
knew which X Y Z to use (although trial and error may help you here
eventually).

Sorry this is confusing, but this is a difficult thing to do and you
should expect to struggle with it for some time, so another questino
to ask yourself is "do I really need to do this?" If its just for
making a movie then you can use pbctools in vmd for that.


Chris.

-- original message --

Hi,  I had a system of surfectants which are started with an initial
configuration where all of them are well dispersed. Visual study of
trajectory shows they start aggregating and finally form two discrete
micelles. To quantify this micelle clusterization, I tried to use the
suggestions present in the gromacs documentations:
http://www.gromacs.org/Documentation/How-tos/Micelle_Clustering
i.e    use

[gmx-users] problem with trjconv -pbc cluster

2010-07-07 Thread chris . neale

PS:

you realize that trjconv -pbc cluster is never going to work unless  
you actually have a cluster, right? So you can't start this procedure  
near your initial dispersed state. You need to start at some time T  
where you actually do have a cluster. Then you can try -dump T, -dump  
(T+X), -dump (T+X*2), etc. Then you can follow the ides expressed  
below like running backwards with -pbc nojup to get the initial state.


Chris.

--original message --

Dear Jagannath:

There is, as far as I know, no way to fix this. Here's what you should do.

1. Let the space between your timesteps be X ps.
2. Use trjconv -pbc cluster -dump X -o out.gro
2b. if that doesn't work, try trjconv -pbc cluster -dump (X*2) -o out.gro
2c. if that doesn't work, try trjconv -pbc cluster -dump (X*3) -o out.gro
...
(Note use real numbers for args to -dump).

Once you have a frame that works, you can run part 2 and 3 of that
wiki page by making a tpr based on the gro that worked -- and I think
that you'll need to run your trjconv -pbc mol starting from the frame
where clustering worked (e.g. -b X). Note that this second requirement
means that you may need to reverse the frames from your .xtc file so
that you can run in reverse time from a complete micelle through to
disassembly with -pbc nojump -- a for loop around trjconv will work
but inefficiently, you might be able to use -demux smartly here (I'm
not sure).

But then since you have 2 micelles you will need a starting box in
which they are both whole getting trickier. You should be aware
that the trjconv -pbc cluster is not the only way to do part 1 from
that wiki page. You could use trjconv -trans X Y Z and then make a new
.tpr and then run trjconv -pbc nojump and it would work if only you
knew which X Y Z to use (although trial and error may help you here
eventually).

Sorry this is confusing, but this is a difficult thing to do and you
should expect to struggle with it for some time, so another questino
to ask yourself is "do I really need to do this?" If its just for
making a movie then you can use pbctools in vmd for that.


Chris.

-- original message --

Hi,  I had a system of surfectants which are started with an initial
configuration where all of them are well dispersed. Visual study of
trajectory shows they start aggregating and finally form two discrete
micelles. To quantify this micelle clusterization, I tried to use the
suggestions present in the gromacs documentations:
http://www.gromacs.org/Documentation/How-tos/Micelle_Clustering
i.euse trjconv -pbc cluster to obtain a single frame that has all
of the lipids in the unit cell. This must be the first frame of your
trajectory. A similar frame from some previous timepoint will not
work.use grompp to make a new tpr file based on the frame that was
output from the step above.use trjconv -pbc nojump to produce the
desired trajectory using the newly produced tpr file.trjconv -f a.xtc
-o a_cluster.gro -e 0.001 -pbc clustergrompp -f a.mdp -c a_cluster.gro
-o a_cluster.tprtrjconv -f a.xtc -o a_cluster.xtc -s a_cluster.tpr
-pbc nojump
But, The first step i.e. trjconv -pbc cluster does not work. Looks
like it is going through an infinite loop and is not stopping for
convergence.
I am using gromacs 4.0.7
Any help will be appreciated.
Jagannath




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[gmx-users] problem with trjconv -pbc cluster

2010-07-07 Thread chris . neale

Dear Jagannath:

There is, as far as I know, no way to fix this. Here's what you should do.

1. Let the space between your timesteps be X ps.
2. Use trjconv -pbc cluster -dump X -o out.gro
2b. if that doesn't work, try trjconv -pbc cluster -dump (X*2) -o out.gro
2c. if that doesn't work, try trjconv -pbc cluster -dump (X*3) -o out.gro
...
(Note use real numbers for args to -dump).

Once you have a frame that works, you can run part 2 and 3 of that  
wiki page by making a tpr based on the gro that worked -- and I think  
that you'll need to run your trjconv -pbc mol starting from the frame  
where clustering worked (e.g. -b X). Note that this second requirement  
means that you may need to reverse the frames from your .xtc file so  
that you can run in reverse time from a complete micelle through to  
disassembly with -pbc nojump -- a for loop around trjconv will work  
but inefficiently, you might be able to use -demux smartly here (I'm  
not sure).


But then since you have 2 micelles you will need a starting box in  
which they are both whole getting trickier. You should be aware  
that the trjconv -pbc cluster is not the only way to do part 1 from  
that wiki page. You could use trjconv -trans X Y Z and then make a new  
.tpr and then run trjconv -pbc nojump and it would work if only you  
knew which X Y Z to use (although trial and error may help you here  
eventually).


Sorry this is confusing, but this is a difficult thing to do and you  
should expect to struggle with it for some time, so another questino  
to ask yourself is "do I really need to do this?" If its just for  
making a movie then you can use pbctools in vmd for that.



Chris.

-- original message --

Hi,  I had a system of surfectants which are started with an initial  
configuration where all of them are well dispersed. Visual study of  
trajectory shows they start aggregating and finally form two discrete  
micelles. To quantify this micelle clusterization, I tried to use the  
suggestions present in the gromacs documentations:  
http://www.gromacs.org/Documentation/How-tos/Micelle_Clustering
i.euse trjconv -pbc cluster to obtain a single frame that has all  
of the lipids in the unit cell. This must be the first frame of your  
trajectory. A similar frame from some previous timepoint will not  
work.use grompp to make a new tpr file based on the frame that was  
output from the step above.use trjconv -pbc nojump to produce the  
desired trajectory using the newly produced tpr file.trjconv -f a.xtc  
-o a_cluster.gro -e 0.001 -pbc clustergrompp -f a.mdp -c a_cluster.gro  
-o a_cluster.tprtrjconv -f a.xtc -o a_cluster.xtc -s a_cluster.tpr  
-pbc nojump
But, The first step i.e. trjconv -pbc cluster does not work. Looks  
like it is going through an infinite loop and is not stopping for  
convergence.

I am using gromacs 4.0.7
Any help will be appreciated.
Jagannath


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Re: [gmx-users] problem with trjconv -pbc cluster

2010-07-07 Thread jagannath mondal
Thanks for the reply. I used following command to extract first frame that has 
all the surfectants ( as suggested by first step for characterizing micelle 
clustering).
   trjconv -f a.xtc -o a_cluster.gro -dump 0 -pbc cluster Here is the output I 
got:COM:    0.000     0.000    19.999  iter = 19526  Isq = 12671033.000COM:    
0.000     0.000     0.000  iter = 19527  Isq = 12628369.000COM:    0.000     
0.000    19.999  iter = 19528  Isq = 12671033.000COM:    0.000     0.000     
0.000  iter = 19529  Isq = 12628369.000COM:    0.000     0.000    19.999  iter 
= 19530  Isq = 12671033.000COM:    0.000     0.000     0.000  iter = 19531  Isq 
= 12628369.000COM:    0.000     0.000    19.999  iter = 19532  Isq = 
12671033.000COM:    0.000     0.000     0.000  iter = 19533  Isq = 
12628369.000COM:    0.000     0.000    19.999  iter = 19534  Isq = 
12671033.000COM:    0.000     0.000     0.000  iter = 19535  Isq = 
12628369.000COM:    0.000     0.000    19.999  iter = 19536  Isq = 
12671033.000COM:    0.000     0.000     0.000  iter = 19537
  Isq = 12628369.000COM:    0.000     0.000    19.999  iter = 19538  Isq = 
12671033.000
looks like lsq is only fluctuating between two numbers and the program is in an 
infinte loop. 
Jagannath 
--- On Wed, 7/7/10, Mark Abraham  wrote:

From: Mark Abraham 
Subject: Re: [gmx-users] problem with trjconv -pbc cluster
To: "Discussion list for GROMACS users" 
Date: Wednesday, 7 July, 2010, 12:20 PM



- Original Message -
From: jagannath mondal 
Date: Wednesday, July 7, 2010 16:36
Subject: [gmx-users] problem with trjconv -pbc cluster
To: gmx-users@gromacs.org

> Hi,  I had a system of surfectants which are started with an initial 
> configuration where all of them are well dispersed. Visual study of 
> trajectory shows they start aggregating and finally form two discrete 
> micelles. > To quantify this micelle clusterization, I tried to use the 
> suggestions present in the gromacs documentations:>  
> http://www.gromacs.org/Documentation/How-tos/Micelle_Clustering> 
> i.e >    > use trjconv -pbc cluster to obtain a single frame that has all of 
> the lipids in the  unit cell. This must be the first frame of your 
> trajectory. A similar frame from some previous timepoint will not work.> 
> use grompp to make a new tpr file based on the frame that was output from the 
> step above.> use trjconv -pbc nojump to produce the desired trajectory using 
> the newly produced tpr file.> trjconv -f a.xtc -o  a_cluster.gro -e 0.001 
> -pbc cluster> grompp -f a.mdp -c a_cluster.gro -o a_cluster.tpr> trjconv -f 
> a.xtc -o a_cluster.xtc -s a_cluster.tpr -pbc nojump
> But, The first step i.e. trjconv -pbc cluster does not work. Looks like it is 
> going through an infinite loop and is not stopping for convergence.

So what command did you give, what output did you get, and does the command 
make sense with respect to your trajectory contents?

Mark

> 
> I am using gromacs 4.0.7> 
> Any help will be appreciated.> 
> Jagannath> 
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Re: [gmx-users] problem with trjconv -pbc cluster

2010-07-06 Thread Mark Abraham


- Original Message -
From: jagannath mondal 
Date: Wednesday, July 7, 2010 16:36
Subject: [gmx-users] problem with trjconv -pbc cluster
To: gmx-users@gromacs.org

---
| > Hi,  I had a system of surfectants which are started with an initial 
configuration where all of them are well dispersed. Visual study of trajectory 
shows they start aggregating and finally form two discrete micelles. > To 
quantify this micelle clusterization, I tried to use the suggestions present in 
the gromacs documentations:>  
http://www.gromacs.org/Documentation/How-tos/Micelle_Clustering> 
> i.e > - > use trjconv -pbc cluster to obtain a single frame that has all 
> of the lipids in the  unit cell. This must be the first frame of your 
> trajectory. A similar frame from some previous timepoint will not work.
 - > use grompp to make a new tpr file based on the frame that was output from 
the step above.
 - > use trjconv -pbc nojump to produce the desired trajectory using the newly 
produced tpr file.

 - > trjconv -f a.xtc -o  a_cluster.gro -e 0.001 -pbc cluster
 - > grompp -f a.mdp -c a_cluster.gro -o a_cluster.tpr
 - > trjconv -f a.xtc -o a_cluster.xtc -s a_cluster.tpr -pbc nojump


> But, The first step i.e. trjconv -pbc cluster does not work. Looks like it is 
> going through an infinite loop and is not stopping for convergence.

So what command did you give, what output did you get, and does the command 
make sense with respect to your trajectory contents?

Mark

> 
> I am using gromacs 4.0.7> 
> Any help will be appreciated.> 
> Jagannath |
---
> 
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[gmx-users] problem with trjconv -pbc cluster

2010-07-06 Thread jagannath mondal
Hi,  I had a system of surfectants which are started with an initial 
configuration where all of them are well dispersed. Visual study of trajectory 
shows they start aggregating and finally form two discrete micelles. To 
quantify this micelle clusterization, I tried to use the suggestions present in 
the gromacs 
documentations: http://www.gromacs.org/Documentation/How-tos/Micelle_Clustering
i.euse trjconv -pbc cluster to obtain a single frame that has all of the 
lipids in the unit cell. This must be the first frame of your trajectory. A 
similar frame from some previous timepoint will not work.use grompp to make a 
new tpr file based on the frame that was output from the step 
above.use trjconv -pbc nojump to produce the desired trajectory using the newly 
produced tpr file.trjconv -f a.xtc -o a_cluster.gro -e 0.001 -pbc 
clustergrompp -f a.mdp -c a_cluster.gro -o a_cluster.tprtrjconv -f a.xtc -o 
a_cluster.xtc -s a_cluster.tpr -pbc nojump
But, The first step i.e. trjconv -pbc cluster does not work. Looks like it is 
going through an infinite loop and is not stopping for convergence.
I am using gromacs 4.0.7
Any help will be appreciated.
Jagannath

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Re: [gmx-users] problem with trjconv

2009-06-08 Thread Mark Abraham

nitu sharma wrote:

Dear all

 I am on the final step of  MD simulation of 
membrane protein . the final mdrun has successfully  completed after 
that I have filtered the water from the system .next step is to convert 
it in final pdb to view it in pymol for this  I am using "trjconv" in 
this step I have to  select a group from this option-


Group 0 (  System) has 419010 elements
Group 1 ( Protein) has  9902 elements
Group 2 (   Protein-H) has  7778 elements
Group 3 ( C-alpha) has  1000 elements
Group 4 (Backbone) has  3000 elements
Group 5 (   MainChain) has  4000 elements
Group 6 (MainChain+Cb) has  4922 elements
Group 7 ( MainChain+H) has  4961 elements
Group 8 (   SideChain) has  4941 elements
Group 9 ( SideChain-H) has  3778 elements
Group10 ( Prot-Masses) has  9902 elements
Group11 ( Non-Protein) has 409108 elements
Group12 (DMPC) has  5520 elements
Group13 ( SOL) has 403578 elements
Group14 ( NA+) has10 elements
Group15 (   Other) has 409108 elements
Select a group:

for protein with lipid bilayer which group is suitable can anyone 
suggest me?


It seems to me that you haven't actually "filtered water", but that you 
may wish to create a suitable index group. See 
http://oldwiki.gromacs.org/index.php/Index_File


Mark

Becoz a/c to my opinion in group 0 there may be water also but I want to 
remove water .

so please if anyone have idea about this please suggest me .

thanks a lot.

Nitu Sharma.




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[gmx-users] problem with trjconv

2009-06-08 Thread nitu sharma
Dear all

 I am on the final step of  MD simulation of membrane
protein . the final mdrun has successfully  completed after that I have
filtered the water from the system .next step is to convert it in final pdb
to view it in pymol for this  I am using "trjconv" in this step I have to
select a group from this option-

Group 0 (  System) has 419010 elements
Group 1 ( Protein) has  9902 elements
Group 2 (   Protein-H) has  7778 elements
Group 3 ( C-alpha) has  1000 elements
Group 4 (Backbone) has  3000 elements
Group 5 (   MainChain) has  4000 elements
Group 6 (MainChain+Cb) has  4922 elements
Group 7 ( MainChain+H) has  4961 elements
Group 8 (   SideChain) has  4941 elements
Group 9 ( SideChain-H) has  3778 elements
Group10 ( Prot-Masses) has  9902 elements
Group11 ( Non-Protein) has 409108 elements
Group12 (DMPC) has  5520 elements
Group13 ( SOL) has 403578 elements
Group14 ( NA+) has10 elements
Group15 (   Other) has 409108 elements
Select a group:

for protein with lipid bilayer which group is suitable can anyone suggest
me?

Becoz a/c to my opinion in group 0 there may be water also but I want to
remove water .
so please if anyone have idea about this please suggest me .

thanks a lot.

Nitu Sharma.
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Re: [gmx-users] problem with trjconv

2008-03-03 Thread Mark Abraham
> Hi all,
> I am trying to use *trjconv command for -pbc but POPC molecules are
> breaking
> when visualize in VMD. The commands  used are
> grompp -f  pr.mdp  -c  em_out.gro -p .top -n index.ndx -o out.tpr
> trjconv  -f em_out.gro  -s out.tpr  -o trj_out.gro  -pbc inbox or cluster
> or
> whole
> Thi trj_out.gro contain broken POPC molecules

GROMACS doesn't ever write molecules that are broken across periodic
boundaries. Thus either you've introduced a visual artefact with your use
of VMD, or your EM produced a broken molecule through using a broken
physical model. You should examine the nature of "broken", and/or try
using ngmx to confirm what is really going on.

Your grompp-trjconv sequence is not necessary for massaging the PBC
behaviour of your EM output. trjconv will accept a .gro file for the -s
flag, which you will see is indicated in the section of the output of
"trjconv -h" that deals with the -s flag. This is quite general GROMACS
behaviour.

Mark

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Re: [gmx-users] problem with trjconv

2008-03-03 Thread Justin A. Lemkul
Quoting sudheer babu <[EMAIL PROTECTED]>:

> Hi all,
> I am trying to use *trjconv command for -pbc but POPC molecules are breaking
> when visualize in VMD. The commands  used are
> grompp -f  pr.mdp  -c  em_out.gro -p .top -n index.ndx -o out.tpr
> trjconv  -f em_out.gro  -s out.tpr  -o trj_out.gro  -pbc inbox or cluster or
> whole

Your scheme will not work because the structure in the .tpr file is the same as
in your em_out.gro, which you claim to be broken.  I'm assuming em_out.gro
refers to your structure following energy-minimization?  And if so, I'm
wondering what you've done that's left a broken molecule following EM.  Is your
em_out.gro whole?

-Justin

> Thi trj_out.gro contain broken POPC molecules
> Pls suggest me what options I have to use for -pbc? or any addition option I
> have to use?
> Thanks in advance...
>





Justin A. Lemkul
Graduate Research Assistant
Department of Biochemistry
Virginia Tech
Blacksburg, VA
[EMAIL PROTECTED] | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin/


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[gmx-users] problem with trjconv

2008-03-03 Thread sudheer babu
Hi all,
I am trying to use *trjconv command for -pbc but POPC molecules are breaking
when visualize in VMD. The commands  used are
grompp -f  pr.mdp  -c  em_out.gro -p .top -n index.ndx -o out.tpr
trjconv  -f em_out.gro  -s out.tpr  -o trj_out.gro  -pbc inbox or cluster or
whole
Thi trj_out.gro contain broken POPC molecules
Pls suggest me what options I have to use for -pbc? or any addition option I
have to use?
Thanks in advance...
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Re: [gmx-users] Problem with trjconv

2007-04-25 Thread Tsjerk Wassenaar

Hi Aline,

You probably missed the part of David's answer that this was probably
fixed in CVS code already? In that case:
This has probably been fixed in CVS code already. Some silly bug, no
particular reasons not to give you a frame at 100ps.

Tsjerk

On 4/25/07, Aline Rossi <[EMAIL PROTECTED]> wrote:


I have a 100ps .trr file. If I use:
trjconv -f in.trr -o out.gro -dump 95 -s in.tpr

trjconv stops returning the following warning:

"Reading frame 20 time 95.000

WARNING no output, trajectory ended at 100"


Same warning if I -dump with any other value, as well with -b 95 -e 95.


Why does the trjconv does not give me the output file? The gromacs version
is 3.3.1.

Thanks for your help.

Aline Rossi

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Junior UD (post-doc)
Biomolecular NMR, Bijvoet Center
Utrecht University
Padualaan 8
3584 CH Utrecht
The Netherlands
P: +31-30-2539931
F: +31-30-2537623
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[gmx-users] Problem with trjconv

2007-04-25 Thread Aline Rossi

*
**I have a 100ps .trr file. If I use:
**trjconv -f in.trr -o out.gro -dump 95 -s in.tpr
**
**trjconv stops returning the following warning:
**"Reading frame  20 time   95.000
**
**WARNING no output, trajectory ended at 100"
**
**
**Same warning if I -dump with any other value, as well with -b 95 -e 95.
**
**Why does the trjconv does not give me the output file? The gromacs
version is 3.3.1.
**
**Thanks for your help.
**
**Aline Rossi*
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[gmx-users] Problem with trjconv

2007-04-22 Thread Aline Rossi

Aline wrote:

* Greetings,

*>*
*>* I have a 100ps .trr file. If I use:
*>* trjconv -f in.trr -o out.gro -dump 95 -s in.tpr
*>*
*>* trjconv stops returning the following warning:
*>* "Reading frame  20 time   95.000
*>*
*>* WARNING no output, trajectory ended at 100"
*>*
*>*
*>* Same warning if I -dump with any other value, as well with -b 95 -e 95.
*>*
*>* Why does the trjconv does not give me the output file?
*>*
*>* Thanks for your help.
*>*
*>* Aline
*>*
*>*
*David wrote:

Which gromacs version?
This has probably been fixed in the development code already.

--
David.


The gromacs version is 3.3.1.

Aline
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Re: [gmx-users] Problem with trjconv

2007-04-20 Thread David van der Spoel

Aline wrote:

Greetings,

I have a 100ps .trr file. If I use:
trjconv -f in.trr -o out.gro -dump 95 -s in.tpr
 
trjconv stops returning the following warning:

"Reading frame  20 time   95.000

WARNING no output, trajectory ended at 100"


Same warning if I -dump with any other value, as well with -b 95 -e 95.

Why does the trjconv does not give me the output file?

Thanks for your help.

Aline



Which gromacs version?
This has probably been fixed in the development code already.

--
David.

David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  75124 Uppsala, Sweden
phone:  46 18 471 4205  fax: 46 18 511 755
[EMAIL PROTECTED]   [EMAIL PROTECTED]   http://folding.bmc.uu.se

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[gmx-users] Problem with trjconv

2007-04-20 Thread Aline

Greetings,

I have a 100ps .trr file. If I use:
trjconv -f in.trr -o out.gro -dump 95 -s in.tpr

trjconv stops returning the following warning:
"Reading frame  20 time   95.000

WARNING no output, trajectory ended at 100"


Same warning if I -dump with any other value, as well with -b 95 -e 95.

Why does the trjconv does not give me the output file?

Thanks for your help.

Aline
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Re: [gmx-users] problem with trjconv

2007-02-28 Thread Mark Abraham

OZGE ENGIN wrote:

Hi,

First of all, thank you for your attention. I used g_hbond in order to analyze  
hydrogen bonds formed;but, I need a more detailed information. The command that 
you mentioned is capable of giving information about hydrogen bonds formed in 
each frame. However, I want to investigate the exact donor and acceptor groups 
in each frame. In this respect, I converted the xtc file to a pdb file  to get 
all of the coordinates of both water and protein molecules.
What should I do?


Gee I sound like a broken record. Have you looked at "man g_hbond" to 
see all of its options?


Mark
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Re: Re: [gmx-users] problem with trjconv

2007-02-28 Thread OZGE ENGIN
Hi,

First of all, thank you for your attention. I used g_hbond in order to analyze  
hydrogen bonds formed;but, I need a more detailed information. The command that 
you mentioned is capable of giving information about hydrogen bonds formed in 
each frame. However, I want to investigate the exact donor and acceptor groups 
in each frame. In this respect, I converted the xtc file to a pdb file  to get 
all of the coordinates of both water and protein molecules.
What should I do?

Thanks in advance

Ozge

-Original Message-
From: "Tsjerk Wassenaar" <[EMAIL PROTECTED]>
To: "Discussion list for GROMACS users" 
Date: Wed, 28 Feb 2007 17:52:34 +0100
Subject: Re: [gmx-users] problem with trjconv

Hi Ozge,

Why do you first want to go to a .pdb trajectory? Gromacs comes with
g_hbond, which can analyze hydrogen bonds for you, as well as giving
you an index file containing the atoms involved in hydrogen bonds,
which you can use to extract those from your trajectory. In addition,
g_hbond also does "normal" contacts, other than hydrogen bonds.

Tsjerk

On 2/28/07, Mark Abraham <[EMAIL PROTECTED]> wrote:
> OZGE ENGIN wrote:
> > Hi,
> >
> > I have a problem with the trjconv command.
> >
> > I performed a 30 ns simulation, and wanted to analyze hydrogen bonds formed 
> > between protein and water molecules. In this respect, I converted the xtc 
> > file into a pdb file by selecting system option. As you can understand the 
> > overall file was such a large file that I could not handle it. So, I want 
> > to know whether there is any possibility to select water molecules within a 
> > cutoff value or to extract frames within  given time steps? For instance, 
> > at every 70 th step, from 70 ps to 80 ps.
>
> If you read the man page for trjconv, you will see an option to do the
> latter. I don't think the former is implemented in the gromacs utilities.
>
> Mark
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--
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Junior UD (post-doc)
Biomolecular NMR, Bijvoet Center
Utrecht University
Padualaan 8
3584 CH Utrecht
The Netherlands
P: +31-30-2539931
F: +31-30-2537623
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Re: [gmx-users] problem with trjconv

2007-02-28 Thread Tsjerk Wassenaar

Hi Ozge,

Why do you first want to go to a .pdb trajectory? Gromacs comes with
g_hbond, which can analyze hydrogen bonds for you, as well as giving
you an index file containing the atoms involved in hydrogen bonds,
which you can use to extract those from your trajectory. In addition,
g_hbond also does "normal" contacts, other than hydrogen bonds.

Tsjerk

On 2/28/07, Mark Abraham <[EMAIL PROTECTED]> wrote:

OZGE ENGIN wrote:
> Hi,
>
> I have a problem with the trjconv command.
>
> I performed a 30 ns simulation, and wanted to analyze hydrogen bonds formed 
between protein and water molecules. In this respect, I converted the xtc file 
into a pdb file by selecting system option. As you can understand the overall file 
was such a large file that I could not handle it. So, I want to know whether there 
is any possibility to select water molecules within a cutoff value or to extract 
frames within  given time steps? For instance, at every 70 th step, from 70 ps to 
80 ps.

If you read the man page for trjconv, you will see an option to do the
latter. I don't think the former is implemented in the gromacs utilities.

Mark
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--
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Junior UD (post-doc)
Biomolecular NMR, Bijvoet Center
Utrecht University
Padualaan 8
3584 CH Utrecht
The Netherlands
P: +31-30-2539931
F: +31-30-2537623
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Re: [gmx-users] problem with trjconv

2007-02-28 Thread Mark Abraham

OZGE ENGIN wrote:

Hi,

I have a problem with the trjconv command. 


I performed a 30 ns simulation, and wanted to analyze hydrogen bonds formed 
between protein and water molecules. In this respect, I converted the xtc file 
into a pdb file by selecting system option. As you can understand the overall 
file was such a large file that I could not handle it. So, I want to know 
whether there is any possibility to select water molecules within a cutoff 
value or to extract frames within  given time steps? For instance, at every 70 
th step, from 70 ps to 80 ps.


If you read the man page for trjconv, you will see an option to do the 
latter. I don't think the former is implemented in the gromacs utilities.


Mark
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[gmx-users] problem with trjconv

2007-02-28 Thread OZGE ENGIN
Hi,

I have a problem with the trjconv command.

I performed a 30 ns simulation, and wanted to analyze hydrogen bonds formed 
between protein and water molecules. In this respect, I converted the xtc file 
into a pdb file by selecting system option. As you can understand the overall 
file was such a large file that I could not handle it. So, I want to know 
whether there is any possibility to select water molecules within a cutoff 
value or to extract frames within  given time steps? For instance, at every 70 
th step, from 70 ps to 80 ps.

Thanks in advance

Ozge

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Re: [gmx-users] Problem with trjconv centering after fitting

2006-08-28 Thread chris . neale
Thanks Tsjerk, that works great! Also your explaination was very clear. I would
just like to follow up that what works for me was (2 steps):

trjconv -s a.tpr -f a.xtc -o b.xtc -center tric -ur compact -pbc none
trjconv -s a.tpr -f b.xtc -o c.xtc -fit rot+trans

I now understand also why the following single step conversion doesn't work, but
perhaps this following combination should be disallowed by trjconv or the code
should be changed to do the rotation as the last step:

trjconv -s a.tpr -f a.xtc -o c.xtc -center tric -ur compact -fit rot+trans -pbc
inbox


> From: "Tsjerk Wassenaar" <[EMAIL PROTECTED]>
> Subject: Re: [gmx-users] Problem with trjconv centering after fitting
> To: "Discussion list for GROMACS users" 
> Message-ID:
>   <[EMAIL PROTECTED]>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> Hi,
> 
> Would that be the same? What happened here is that the system was
> first fitted. Thus, the system is rotated and any operation concerning
> pbc after that point will be screwed up, because the box definition
> does not match the system. Solution: first perform all operations
> involving pbc, then fit the system. Note that translations are not a
> problem, only rotations. An alternative solution would be to have all
> routines involving rotation of the frame also rotating the box
> definition in that frame in the trajectory. But this requires
> modifications in many routines.
> 
> Tsjerk
> 
> On 8/28/06, David van der Spoel <[EMAIL PROTECTED]> wrote:
> > [EMAIL PROTECTED] wrote:
> > > Starting from a rhombic dodecahedron xtc file,
> > >
> > > trjconv -fit rot+trans -f a.xtc -s a.tpr -o a_fit.xtc
> > > trjconv -center rect -pbc whole -f a_fit.xtc -s a.tpr -o a_fit_cent.xtc
> > >
> > > Visualization of a.xtc and a_fit.xtc via VMD are as expected.
> Nevertheless,
> > > a_fit_cent.xtc shows overlapping atoms and regions of zero density. Why
> is this?
> > >
> > > ___
> > > gmx-users mailing listgmx-users@gromacs.org
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> > could this be the same problem as reported here:
> >
> > http://bugzilla.gromacs.org/show_bug.cgi?id=99
> >
> > --
> > David.
> > 
> > David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
> > Dept. of Cell and Molecular Biology, Uppsala University.
> > Husargatan 3, Box 596,  75124 Uppsala, Sweden
> > phone:  46 18 471 4205  fax: 46 18 511 755
> > [EMAIL PROTECTED][EMAIL PROTECTED]   http://folding.bmc.uu.se
> > 
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> >
> 
> 
> -- 
> 
> Tsjerk A. Wassenaar, M.Sc.
> Groningen Biomolecular Sciences and Biotechnology Institute (GBB)
> Dept. of Biophysical Chemistry
> University of Groningen
> Nijenborgh 4
> 9747AG Groningen, The Netherlands
> +31 50 363 4336
> 
> 
> --
> 
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> 
> End of gmx-users Digest, Vol 28, Issue 81
> *
> 


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Re: [gmx-users] Problem with trjconv centering after fitting

2006-08-28 Thread Tsjerk Wassenaar

Hi,

Would that be the same? What happened here is that the system was
first fitted. Thus, the system is rotated and any operation concerning
pbc after that point will be screwed up, because the box definition
does not match the system. Solution: first perform all operations
involving pbc, then fit the system. Note that translations are not a
problem, only rotations. An alternative solution would be to have all
routines involving rotation of the frame also rotating the box
definition in that frame in the trajectory. But this requires
modifications in many routines.

Tsjerk

On 8/28/06, David van der Spoel <[EMAIL PROTECTED]> wrote:

[EMAIL PROTECTED] wrote:
> Starting from a rhombic dodecahedron xtc file,
>
> trjconv -fit rot+trans -f a.xtc -s a.tpr -o a_fit.xtc
> trjconv -center rect -pbc whole -f a_fit.xtc -s a.tpr -o a_fit_cent.xtc
>
> Visualization of a.xtc and a_fit.xtc via VMD are as expected. Nevertheless,
> a_fit_cent.xtc shows overlapping atoms and regions of zero density. Why is 
this?
>
> ___
> gmx-users mailing listgmx-users@gromacs.org
> http://www.gromacs.org/mailman/listinfo/gmx-users
> Please don't post (un)subscribe requests to the list. Use the
> www interface or send it to [EMAIL PROTECTED]
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could this be the same problem as reported here:

http://bugzilla.gromacs.org/show_bug.cgi?id=99

--
David.

David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  75124 Uppsala, Sweden
phone:  46 18 471 4205  fax: 46 18 511 755
[EMAIL PROTECTED][EMAIL PROTECTED]   http://folding.bmc.uu.se

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--

Tsjerk A. Wassenaar, M.Sc.
Groningen Biomolecular Sciences and Biotechnology Institute (GBB)
Dept. of Biophysical Chemistry
University of Groningen
Nijenborgh 4
9747AG Groningen, The Netherlands
+31 50 363 4336
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Re: [gmx-users] Problem with trjconv centering after fitting

2006-08-27 Thread David van der Spoel

[EMAIL PROTECTED] wrote:

Starting from a rhombic dodecahedron xtc file,

trjconv -fit rot+trans -f a.xtc -s a.tpr -o a_fit.xtc
trjconv -center rect -pbc whole -f a_fit.xtc -s a.tpr -o a_fit_cent.xtc

Visualization of a.xtc and a_fit.xtc via VMD are as expected. Nevertheless,
a_fit_cent.xtc shows overlapping atoms and regions of zero density. Why is this?

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could this be the same problem as reported here:

http://bugzilla.gromacs.org/show_bug.cgi?id=99

--
David.

David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  75124 Uppsala, Sweden
phone:  46 18 471 4205  fax: 46 18 511 755
[EMAIL PROTECTED]   [EMAIL PROTECTED]   http://folding.bmc.uu.se

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[gmx-users] Problem with trjconv centering after fitting

2006-08-27 Thread chris . neale
Starting from a rhombic dodecahedron xtc file,

trjconv -fit rot+trans -f a.xtc -s a.tpr -o a_fit.xtc
trjconv -center rect -pbc whole -f a_fit.xtc -s a.tpr -o a_fit_cent.xtc

Visualization of a.xtc and a_fit.xtc via VMD are as expected. Nevertheless,
a_fit_cent.xtc shows overlapping atoms and regions of zero density. Why is this?

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