On 07/27/2011 03:38 PM, Justin A. Lemkul wrote:

Please make sure to keep the discussion on the list.

Sorry, I just was continuing the discussion after sending you my coordinates.


Fabio Affinito wrote:
Justin,
first of all, I thank you very much for your help: it's very precious.
I regret I didn't notice before the molecule was broken.

I suggested to you yesterday that your initial configuration was broken.
You told me it wasn't.

I checked with VMD but I was in error. I acknowledged my error, I think. Didn't I?


Unfortunately the problem is not solved with your recipe. I used
trjconv on the starting configuration and then I used the genconf.
The mdrun fails with the same error. In this case, the atoms involved
in the error are not the same of the previous one. But once again the
bond length is completely odd.
During the grompp I had some warning, but I can't understand where
they are coming from:


Certain bonded interactions can't take place between massless particles.
As the warning states, if pdb2gmx produced the topology, don't worry
about it.

Cleaning up constraints and constant bonded interactions with virtual
sites
Removed 1305 Angles with virtual sites, 6251 left
Removed 480 Proper Dih.s with virtual sites, 363 left
Converted 2230 Constraints with virtual sites to connections, 2596 left
Warning: removed 582 Constraints with vsite with Virtual site 3out
construction
This vsite construction does not guarantee constant bond-length
If the constructions were generated by pdb2gmx ignore this warning
Cleaning up constraints and constant bonded interactions with virtual
sites
Removed 1305 Angles with virtual sites, 6251 left
Removed 480 Proper Dih.s with virtual sites, 363 left
Converted 2230 Constraints with virtual sites to connections, 2596 left
Warning: removed 582 Constraints with vsite with Virtual site 3out
construction
This vsite construction does not guarantee constant bond-length
If the constructions were generated by pdb2gmx ignore this warning
Cleaning up constraints and constant bonded interactions with virtual
sites
Removed 1305 Angles with virtual sites, 6251 left
Removed 480 Proper Dih.s with virtual sites, 363 left
Converted 2230 Constraints with virtual sites to connections, 2596 left
Warning: removed 582 Constraints with vsite with Virtual site 3out
construction
This vsite construction does not guarantee constant bond-length
If the constructions were generated by pdb2gmx ignore this warning
Cleaning up constraints and constant bonded interactions with virtual
sites
Removed 1305 Angles with virtual sites, 6251 left
Removed 480 Proper Dih.s with virtual sites, 363 left
Converted 2230 Constraints with virtual sites to connections, 2596 left
Warning: removed 582 Constraints with vsite with Virtual site 3out
construction
This vsite construction does not guarantee constant bond-length
If the constructions were generated by pdb2gmx ignore this warning

According to your experience, this can be pertinent with my problems?


Not likely. The virtual sites are within the protein, not the lipids,
right?

Without the mdrun output, there's little else I can tell you.

This is the mdrun output:

Initializing Domain Decomposition on 4096 nodes
Dynamic load balancing: auto
Will sort the charge groups at every domain (re)decomposition
Initial maximum inter charge-group distances:
    two-body bonded interactions: 30.031 nm, LJ-14, atoms 40702 40705
  multi-body bonded interactions: 30.031 nm, Angle, atoms 40701 40704
Minimum cell size due to bonded interactions: 33.035 nm
Maximum distance for 7 constraints, at 120 deg. angles, all-trans: 1.139 nm
Estimated maximum distance required for P-LINCS: 1.139 nm
Guess for relative PME load: 0.43
Will use 2400 particle-particle and 1696 PME only nodes
This is a guess, check the performance at the end of the log file
Using 1696 separate PME nodes
Scaling the initial minimum size with 1/0.8 (option -dds) = 1.25
Optimizing the DD grid for 2400 cells with a minimum initial size of 41.293 nm
The maximum allowed number of cells is: X 0 Y 0 Z 0

-------------------------------------------------------
Program mdrun_mpi_bg, VERSION 4.5.4
Source code file: domdec.c, line: 6438

Fatal error:
There is no domain decomposition for 2400 nodes that is compatible with the given box and a minimum cell size of 41.2932 nm
Change the number of nodes or mdrun option -rdd or -dds
Look in the log file for details on the domain decomposition
For more information and tips for troubleshooting, please check the GROMACS
website at http://www.gromacs.org/Documentation/Errors
-------------------------------------------------------

Fabio



-Justin

Thank you once again,

Fabio

On 07/27/2011 02:45 PM, Justin A. Lemkul wrote:

The problem is indeed as I suspected. Your molecules are broken across
periodic boundaries in the initial configuration. When you replicate
with genbox, you've now replicated broken molecules such that those at
the new interfaces between the boxes appear to be intact, but in fact
they are not. This is just an artifact of visualization. If you use
"trjconv -pbc whole" on the original starting configuration to make the
molecules whole before replicating with genconf -nbox, you will avoid
this problem.

-Justin

Fabio Affinito wrote:
Yes. It's in attachment.

Fabio

On 07/27/2011 02:38 PM, Justin A. Lemkul wrote:

Can you please also send me the coordinate file from before you ran
genconf?

-Justin

Fabio Affinito wrote:
Finally, I just got the right compression to fit my file in an
attachment.
The interesting lines are:
159988 and 159992

Kindly regards,

Fabio

On 07/27/2011 01:42 PM, Justin A. Lemkul wrote:


Fabio Affinito wrote:
On 07/26/2011 07:02 PM, Justin A. Lemkul wrote:


Fabio Affinito wrote:
On 07/26/2011 05:06 PM, Justin A. Lemkul wrote:


Fabio Affinito wrote:
Maybe this is a different issue... but it's ok that after the
99,999th
atom the counter restarts from zero?

21374SOL OW99999 12.986 9.021 7.036 -0.0037 -0.4345 0.3977
21374SOL HW1 0 13.069 8.987 7.081 0.5916 0.5409 0.0638

Could this be the origin of my problem?


Atom numbering is not the problem. This happens all the time for
systems
of hundreds of thousands of atoms, which Gromacs handles just
fine.
Please investigate the points I suggested before.

Yes, but this doesn't make things easier! :-)
According to the log the atoms to consider are 159986 and 159990


That's not what you posted before. The .log output indicated atoms
193657 and 193660 were problematic.

Sorry. It's because I've tried with many systems (with different
-nbox
values) and the error was always the same.


Browsing the conf.gro, if I didn't make mistakes this atoms are:

30040POPG OE59986 0.080 13.158 2.964 0.0885 0.4154 -0.0859

30040POPG C1C59990 0.219 26.034 3.221 0.6449 0.0750 0.1313

But their distance is 12.8nm, while md.log reports 38.911 nm...


In any case, why are atoms four bonds (based on the original .log
output
of 1-4 interactions being a problem) away separated by 12.8 nm?
Seems
very odd to me. I ask yet again - what are your box vectors,
before
and
after manipulation with genconf?


Seems odd to me, too. For the box vectors (sorry if I didnt answer
before), in this case:

after: 26.04658 26.04658 8.75317
before: 13.02329 13.02329 8.75317

Hope it helps.


Without seeing the coordinate files, I can't tell anything
further. If
you want, you can send me (off-list) the coordinate files before and
after genconf and please tell me the exact atoms that are
reported as
problematic.

-Justin

Best regards,

Fabio


-Justin

So what?

F.





-Justin

Thanks again,

Fabio

On 07/26/2011 04:38 PM, Justin A. Lemkul wrote:


Fabio Affinito wrote:
On 07/26/2011 04:30 PM, Justin A. Lemkul wrote:


Fabio Affinito wrote:
On 07/26/2011 04:19 PM, Justin A. Lemkul wrote:


Were the molecules whole in the coordinate file you
replicated? If
not,
the bonds will now be assigned across the entire box.

-Justin

Yes and not, depending on what you mean by "whole".
It is an ion channel, so it's made of four chains.
This clarifies? (i guess not..)

By whole, I mean that the molecules are not split across
periodic
boundaries in the initial configuration that you
replicated. If
you
replicate a periodic break, then you split the molecules
by a
distance
equal to the new periodic distance.

-Justin

Ok, so: no, it's not broken.


What you need to do is use the information mdrun provided
you to
diagnose what's going on. Apparently atoms 193657 193660 are
separated
by 31 nm. What are your box vectors? Where are these atoms in
the
system? Then you'll have your answer. The only reason I can
think
of for
such extreme distances is a periodicity issue.

-Justin





















--
Fabio Affinito, PhD
SuperComputing Applications and Innovation Department
CINECA - via Magnanelli, 6/3, 40033 Casalecchio di Reno (Bologna) - ITALY
Tel: +39 051 6171794  Fax: +39 051 6132198
--
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/Support/Mailing_Lists/Search before posting!
Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org.
Can't post? Read http://www.gromacs.org/Support/Mailing_Lists

Reply via email to