Re: [gmx-users] Pressure coupling problem

2011-04-11 Thread Peter C. Lai
So your density graph looks stabilized? I also tend to look for changes in box x, y, z as well since the scale of their changes is easier to track. Sometimes it helps to look at the error vs. rmsd vs total drift statistics as well for such parameters that are easier to track - again if density sh

Re: [gmx-users] Pressure coupling problem

2011-04-11 Thread Justin A. Lemkul
Fabian Casteblanco wrote: Hi, I'm still in my first few months of using Gromacs. I started by creating an *.itp and *.top file for /Ethanol/ using CHARMM force field parameters. I made the molecule and it looked fine, put 1000 molecules in a box, energy minimized it to a negative potenti

Re: [gmx-users] Pressure Coupling Problem

2009-04-13 Thread Lucio Montero
bject: Re: [gmx-users] Pressure Coupling Problem I finally figured it out. I went through every parameter step by step and it turns our I had epsilon-r set to 80. Not sure why I had that. Wish gromacs would have given me a warning (hint hint). That explains why my P.E. was 10^-5 instead of

Re: [gmx-users] Pressure Coupling Problem

2009-04-10 Thread Joe Joe
I finally figured it out. I went through every parameter step by step and it turns our I had epsilon-r set to 80. Not sure why I had that. Wish gromacs would have given me a warning (hint hint). That explains why my P.E. was 10^-5 instead of 10^-6. Thanks everyone for trying!!!. Sometime the most o

Re: [gmx-users] Pressure Coupling Problem

2009-04-09 Thread Joe Joe
Nope not an A/nm problem. As a simple test I take spc.gro from share/top. I reconfigure the box (i.e. editconf -f spc.gro -d 1.0 -c -bt cubic -o water_center. I then solvate with genbox, minimize and run using the mdp file I provided earlier. No matter how much minimization I do the volume of the

Re: [gmx-users] Pressure Coupling Problem

2009-04-09 Thread Joe Joe
On Thu, Apr 9, 2009 at 6:36 AM, Justin A. Lemkul wrote: > > > Joe Joe wrote: > >> So I got my small water box (800 waters) to behave stably with pressure >> coupling after more minimization but I still can't get my large system to >> work with pressure coupling. I tried minimizing but I can never

Re: [gmx-users] Pressure Coupling Problem

2009-04-09 Thread Justin A. Lemkul
Joe Joe wrote: So I got my small water box (800 waters) to behave stably with pressure coupling after more minimization but I still can't get my large system to work with pressure coupling. I tried minimizing but I can never get the Fmax to be less 10^2, which is pretty normal for protein/wat

Re: [gmx-users] Pressure Coupling Problem

2009-04-09 Thread Joe Joe
So I got my small water box (800 waters) to behave stably with pressure coupling after more minimization but I still can't get my large system to work with pressure coupling. I tried minimizing but I can never get the Fmax to be less 10^2, which is pretty normal for protein/water simulations of lar

Re: [gmx-users] Pressure Coupling Problem

2009-04-08 Thread Joe Joe
On Wed, Apr 8, 2009 at 11:31 AM, Roland Schulz wrote: > > > On Wed, Apr 8, 2009 at 7:53 AM, Joe Joe wrote: > >> HI Chris, >> >> On Tue, Apr 7, 2009 at 9:31 PM, wrote: >> >>> Hi Ilya, >>> >>> First thing that comes to mind is that it is strange to couple a >>> coulombic switching function with P

Re: [gmx-users] Pressure Coupling Problem

2009-04-08 Thread Joe Joe
I tried .1, and 10 ps tau_p values. I guess I can try smaller values. On Wed, Apr 8, 2009 at 10:44 AM, Justin A. Lemkul wrote: > > > Joe Joe wrote: > >> Hi Chris, >> >> When I create the topology for the 4fs timestep I use pdb2gmx -vsite h. I >> set up the correct constraints. I've tested it a

Re: [gmx-users] Pressure Coupling Problem

2009-04-08 Thread Joe Joe
Yeah I only gave a partial. Tried to remove the QM params. I do use constraints = all-bonds. On Wed, Apr 8, 2009 at 9:18 AM, wrote: > You say "I run all he sims with constraints=all-bonds", but I don't see > that in the mdp options that you provided. I even put your text in a file > and grepped

Re: [gmx-users] Pressure Coupling Problem

2009-04-08 Thread Roland Schulz
On Wed, Apr 8, 2009 at 7:53 AM, Joe Joe wrote: > HI Chris, > > On Tue, Apr 7, 2009 at 9:31 PM, wrote: > >> Hi Ilya, >> >> First thing that comes to mind is that it is strange to couple a coulombic >> switching function with PME. While this could possibly be done correctly, I >> doubt that it is

Re: [gmx-users] Pressure Coupling Problem

2009-04-08 Thread Justin A. Lemkul
Joe Joe wrote: Hi Chris, When I create the topology for the 4fs timestep I use pdb2gmx -vsite h. I set up the correct constraints. I've tested it and it conserves energy in NVE. I run all he sims with constraints=all-bonds. I am now running a single water box (800 water molecules) with 1s t

Re: [gmx-users] Pressure Coupling Problem

2009-04-08 Thread Joe Joe
Hi Chris, When I create the topology for the 4fs timestep I use pdb2gmx -vsite h. I set up the correct constraints. I've tested it and it conserves energy in NVE. I run all he sims with constraints=all-bonds. I am now running a single water box (800 water molecules) with 1s time steps and the volum

Re: [gmx-users] Pressure Coupling Problem

2009-04-08 Thread Joe Joe
HI Chris, On Tue, Apr 7, 2009 at 9:31 PM, wrote: > Hi Ilya, > > First thing that comes to mind is that it is strange to couple a coulombic > switching function with PME. While this could possibly be done correctly, I > doubt that it is in fact done in the way that you expect (i.e. correctly) in