Re: [gmx-users] restart md from the point it had stopped

2007-10-09 Thread Mark Abraham
sarbani chattopadhyay wrote: hi, I have been running a molecular dynamics simulation for 2 nanoseconds.But it stopped in the middle because of an internal problem.Is there any way to restart the simulation from the point it has stopped? See

[gmx-users] No scale up beyond 4 processors for 240000 atom system

2007-10-09 Thread maria goranovic
Hello, I was wondering what the scale up was with GROMACS 3.3.1 on 8 or 16 processors. Here are my benchmarks: Hardware: Dell PowerEdge 2950, 2x 2,66Ghz Intel Woodcrest CPUs, 8 GB Ram, 2x Gigabit Ethernet GROMACS 3.3.1: 24 atoms, PME, 1.0 nm real cutoff processors ns/day 1 0.141 2

[gmx-users] Wall Potential

2007-10-09 Thread Huey Ling Tan
Hi all, I am trying to simulate multiple (2 or 3) tetrapeptides in a cage with Gromacs. However, I would like to constrain the peptides to the centre of the box by enforcing a wall potential in which each of the atoms of the peptide feels a repulsive potential with respect to the edge of the box

RE: [gmx-users] No scale up beyond 4 processors for 240000 atom system

2007-10-09 Thread Berk Hess
From: maria goranovic [EMAIL PROTECTED] Reply-To: Discussion list for GROMACS users gmx-users@gromacs.org To: gmx-users@gromacs.org Subject: [gmx-users] No scale up beyond 4 processors for 24 atom system Date: Tue, 9 Oct 2007 12:09:50 +0200 Hello, I was wondering what the scale up was

Re: [gmx-users] No scale up beyond 4 processors for 240000 atom system

2007-10-09 Thread Christian Burisch
Berk Hess schrieb: Hi all, So this is 4 cores sharing one ethernet connection? perhaps the two Gigabit NICs were bundled somehow. But I guess this doesn't work out-of-the-boxplug'n'play. And latency and not bandwidth may be limiting in this case. With such a setup you will never get

Re: [gmx-users] only one cpu works in my linux cluster

2007-10-09 Thread Alan Dodd
Yeah. Check the machinefile tells mpich what you think it does. It looks pretty certain to be an issue with mpich rather than gromacs. Unfortunately, I don't use mpich any more because I find LAM better. Standard procedure, turn up the verbosity on everything, check the outputs, re-read the

Re: [gmx-users] only one cpu works in my linux cluster

2007-10-09 Thread liu xin
Thanks for your quick comment Alan :) On 10/9/07, Alan Dodd [EMAIL PROTECTED] wrote: Yeah. Check the machinefile tells mpich what you think it does. It looks pretty certain to be an issue with mpich rather than gromacs. Unfortunately, I don't use mpich any more because I find LAM better.

[gmx-users] limit on energygrp_table

2007-10-09 Thread Adrien Leygue
Dear Gromacs users (and developpers) I need to use a force field, derived from ab initio methods, for which the non-bonded interactions between the different atom types is a modified 3-parameters LJ potential. As this kind of potential is not implemented within Gromacs I am using fully tabulated

RE: [gmx-users] limit on energygrp_table

2007-10-09 Thread Berk Hess
From: Adrien Leygue [EMAIL PROTECTED] Reply-To: Discussion list for GROMACS users gmx-users@gromacs.org To: gmx-users@gromacs.org Subject: [gmx-users] limit on energygrp_table Date: Tue, 9 Oct 2007 18:13:21 +0300 Dear Gromacs users (and developpers) I need to use a force field, derived from

Re: [gmx-users] solubility of PVME in TIP5P

2007-10-09 Thread JW Feng
Did you noticed that the number of TIP5P water molecules is about half of what's needed to fill the box. I think that's why your box collapsed. JW On 4/23/07, kitty ji [EMAIL PROTECTED] wrote: Dear GMX user, Explicated model of Poly (vinyl methyl ether) was built with ether parameters

[gmx-users] simulating Hexadecane in water

2007-10-09 Thread Adam Fraser
Hello, I'm very new to Gromacs, and I am interested in simulating the interactions of 2 hexadecane (C16H34) molecules in water (SPC/E specificall). I've spent some time experimenting with tutorials in Gromacs, but I've found little help in non-protein simulations like this one. I have built

[gmx-users] 3.3.2 Error when using the mpi option

2007-10-09 Thread Triguero, Luciano O
Hi, I am trying to compile version 3.3.2 in the parallel mode. I use the following options to configure: ./configure --prefix=dir --disable-float -enable-mpi and receive the following error message: checking size of int... configure: error: cannot compute sizeof (int) Note: The non

Re: [gmx-users] restart md from the point it had stopped

2007-10-09 Thread Diego Enry
[Tsjerk] why do you write velocities and forces every 10 ps? Third world country my friend, energy supply is not that stable over here. Also the queue to run a process is huuuge, so every hour is important. In the end I do a trjconv to reduce # of frames. Great Doing Restarts whoever wrote it :D

Re: [gmx-users] 3.3.2 Error when using the mpi option

2007-10-09 Thread Erik Lindahl
Hi, On Oct 9, 2007, at 6:21 PM, Triguero, Luciano O wrote: Hi, I am trying to compile version 3.3.2 in the parallel mode. I use the following options to configure: ./configure --prefix=dir --disable-float -enable-mpi and receive the following error message: checking size of int...

[gmx-users] grompp error

2007-10-09 Thread chris . neale
hi... i have been trying to do grompp for the following file but am getting this error: There were 1 error(s) processing your inputWARNING 3 [file popc.top, line 32]: 7380 non-matching atom names atom names from popc.top will be used atom names from popc.pdb will be ignored Your

Re: [gmx-users] No scale up beyond 4 processors for 240000 atom system

2007-10-09 Thread Diego Enry
Low cost tip: Ask your cluster administrator if it is possible apply channel bonding to the Gigabit interfaces. You need two network switches for that to be efficient (a cut-through switch may also help). It increases network bandwidth by 70%. It also helps to use Cat6 cables. You may try this

[gmx-users] grompp error

2007-10-09 Thread chris . neale
ERROR: The cut-off length is longer than half the shortest box vector or longer than the smallest box diagonal element. Increase the box size or decrease rlist. try to Increase the box size or decrease rlist. = as ERROR message suggests Yes, technically you could decrease rlist (rcoulomb

[gmx-users] Criteria and Energy Conservation

2007-10-09 Thread gtroiano
Dear GROMACS Users, I'm trying to use GROMACS to get some MD snapshots for single-point quantum mechanical calculations, trying to observe HOMO-LUMO gap of a protein immersed in water with counterions, at a given salt concentration (4600 atoms in total). I'd like to know if they are reliable

[gmx-users] Re: 3.3.2 trjconv -ur compact -pbc whole problem

2007-10-09 Thread JW Feng
GMX users, In 3.3.1, I used trjconv -ur compact -pbc whole to convert a rhombic dodecahedron box so it could be displayed properly in VMD. This does not appear to be working in 3.3.2. Is there another way to convert a box so it displays properly in a visualization program? This is the command

[gmx-users] How to change the box size during simuation

2007-10-09 Thread WU Yanbin
Hey, Now I'm simulating infinite molecules. I want to change the box size a lit bit every time step so as to induce some stress in this system. Is there any way in gromacs to do this, apart from modifying the code? Thanks in advance. Yours Sincerely,

[gmx-users] Re: 3.3.2 trjconv -ur compact -pbc whole problem

2007-10-09 Thread JW Feng
Using trjconv -ur compact -pbc atom worked. JW On 10/9/07, JW Feng [EMAIL PROTECTED] wrote: GMX users, In 3.3.1, I used trjconv -ur compact -pbc whole to convert a rhombic dodecahedron box so it could be displayed properly in VMD. This does not appear to be working in 3.3.2. Is there

[gmx-users] Fatal error: Atom CA not found in residue LYSH200 while adding hydrogens

2007-10-09 Thread Haining Liu
Hi, I have a problem using Gromacs. When I use the pdb2gmx command to generate the .top and .gro files, I got the error: :-) G R O M A C S (-: Gyas ROwers Mature At Cryogenic Speed :-) VERSION 3.3.2 (-:

Re: [gmx-users] Fatal error: Atom CA not found in residue LYSH200 while adding hydrogens

2007-10-09 Thread Tsjerk Wassenaar
Haining, Did you check the structure for missing atoms/residues (REMARK 465/470)? Tsjerk On 10/10/07, Haining Liu [EMAIL PROTECTED] wrote: Hi, I have a problem using Gromacs. When I use the pdb2gmx command to generate the .top and .gro files, I got the error:

Re: [gmx-users] Fatal error: Atom CA not found in residue LYSH200 while adding hydrogens

2007-10-09 Thread Haining Liu
Tsjerk,I just started to learn Gromacs. But how do I check the missing atoms?Thanks,HainingOn Wed, 10 Oct 2007 06:41:31 +0200 Tsjerk Wassenaar <[EMAIL PROTECTED] />wrote: Haining, Did you check the structure for missing atoms/residues (REMARK 465/470)? Tsjerk On 10/10/07, Haining Liu

Re: [gmx-users] Fatal error: Atom CA not found in residue LYSH200 while adding hydrogens

2007-10-09 Thread Tsjerk Wassenaar
Hi Haining, This has nothing to do with gromacs. The information is in the .pdb file (use a text viewer/editor). Before starting any simulation, you have to know what you're intending to simulate. The model, the .pdb file of it. How the structure was solved, etc., etc. The paper should also state

[gmx-users] anisotropic pressure coupling for temperature annealing

2007-10-09 Thread Q733
Dear gmx-users, I used anisotropic p-coupling for lipid bilayers and annealed the system from 330K-300K at the ratio of 2 degree/ns.And the x dimension and y dimension increased with time in the whole procedure, but actually the area/lipid should decrease when tempreture decreases. I think

Re: [gmx-users] anisotropic pressure coupling for temperature annealing

2007-10-09 Thread Mark Abraham
Q733 wrote: Dear gmx-users, I used anisotropic p-coupling for lipid bilayers and annealed the system from 330K-300K at the ratio of 2 degree/ns.And the x dimension and y dimension increased with time in the whole procedure, but actually the area/lipid should decrease when tempreture