[gmx-users] structure factor

2012-08-16 Thread Tetsuo Shu
Dear gmx users. I am new for MD and am learning hard but need to ask simple question,,, I have co2 + water system. I understand RDF and it can calculate with g_rdf by choosing 2 species like o-o, c-o, etc. It is good! I also want to learn structure factor. But for structure factor can only choos

Re: [gmx-users] LINCS

2012-08-16 Thread Mark Abraham
On 17/08/2012 2:56 PM, shahid nayeem wrote: I want to simulate without building the missing residue. Does gromacs have an option of capping. I am using Gromacs 4.5.4. If not then suggest some software which I may use. All you can do is use pdb2gmx as you do for the normal termini. pdb2gmx -cha

Re: [gmx-users] LINCS

2012-08-16 Thread shahid nayeem
I want to simulate without building the missing residue. Does gromacs have an option of capping. I am using Gromacs 4.5.4. If not then suggest some software which I may use. Shahid nayeem On Fri, Aug 17, 2012 at 10:03 AM, Mark Abraham wrote: > On 17/08/2012 2:28 PM, shahid nayeem wrote: >> >> Rig

Re: [gmx-users] LINCS

2012-08-16 Thread Mark Abraham
On 17/08/2012 2:28 PM, shahid nayeem wrote: Right, I have a pdb where some of the residues are missing and when I try to simulate it I get LINCS warning in between the atom of the two ends of missing residues. So if I use a smaller time step (0.01) for final production run and energy minimization

Re: [gmx-users] LINCS

2012-08-16 Thread shahid nayeem
Right, I have a pdb where some of the residues are missing and when I try to simulate it I get LINCS warning in between the atom of the two ends of missing residues. So if I use a smaller time step (0.01) for final production run and energy minimization with setting constraint = none, making it com

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Shima Arasteh
 :-)   Thanks Peter. Sincerely, Shima - Original Message - From: Peter C. Lai To: Shima Arasteh Cc: Discussion list for GROMACS users Sent: Friday, August 17, 2012 8:48 AM Subject: Re: [gmx-users] Protein-POPC bilayer On 2012-08-16 09:04:35PM -0700, Shima Arasteh wrote: > > > Oh

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Peter C. Lai
On 2012-08-16 09:04:35PM -0700, Shima Arasteh wrote: > > > Oh, It's OK. Thanks Peter. :-) > I used the the same .mdp file sent me by you 1 month ago, for the > pre-equilibration of POPC in water. > Well if that worked out, then what is the problem? What do you mean by "pre-equlibration" The

Re: [gmx-users] LINCS

2012-08-16 Thread Mark Abraham
On 17/08/2012 2:02 PM, shahid nayeem wrote: Dear all One basic clarification. How does LINCS algorithm influences the results of final production run. In what respect a minimization, pr and final simulation done with constraints = none and with constraint= all_bonds are different. Sounds like

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Shima Arasteh
Oh, It's OK. Thanks Peter. :-) I used the the same .mdp file sent me by you 1 month ago, for the pre-equilibration of POPC in water. But as others said here, anisotropic pressure coupling might result in major changes in lipid bilayer. I don't know, but it seems it is better to use anisotrop

[gmx-users] LINCS

2012-08-16 Thread shahid nayeem
Dear all > One basic clarification. How does LINCS algorithm influences the results > of final production run. In what respect a minimization, pr and final > simulation done with constraints = none and with constraint= all_bonds are > different. > Shahid Nayeem -- gmx-users mailing listgmx-use

Re: [gmx-users] Questions regarding Polarization Energy Calculation

2012-08-16 Thread Mark Abraham
On 17/08/2012 1:14 PM, jesmin jahan wrote: Hi Mark, According to your advice " remove the the bonded terms and zero the VDW parameters", I removed everything under [ bond] , [angles], [pairs] and [ dihedrals ], This only removes the "bonded" terms (in the sense of those atoms that interact

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Peter C. Lai
Can't remember why I said that, since it's not what I used. Stupid autocorrect? Sorry! On 2012-08-16 08:35:23PM -0700, Shima Arasteh wrote: > In  "2.1.6. Membrane bilayer construction" part of the article you mentioned: > > Asingle POPC molecule is parameterized using a > CHARMM36 force field co

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Shima Arasteh
In  "2.1.6. Membrane bilayer construction" part of the article you mentioned: Asingle POPC molecule is parameterized using a CHARMM36 force field conversion for GROMACS7. The result- ing system,which consists of around 238 lipids is then equilibrated for at least 50 ns at 310 K and 1 atm under NPT

Re: [gmx-users] Questions regarding Polarization Energy Calculation

2012-08-16 Thread jesmin jahan
Hi Mark, According to your advice " remove the the bonded terms and zero the VDW parameters", I removed everything under [ bond] , [angles], [pairs] and [ dihedrals ], and run the simulation mdrun rerun. I got output something like the following: Energies (kJ/mol) GB PolarizationL

RE: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Dallas Warren
Not directly related to bilayers, but our work with liquid phases has found some interesting things with anisotropic versus isotropic. Basically, even though anisotropic allows things to structure without constraints to how they want to be, there is some artifacts that drive it too far, beyond

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Peter C. Lai
Here is my MDP file I use for POPC work for NPT-after-NVT equilibration, in caes you lost it from the time before: You can choose to use V-rescale and Berendsen if you want but the Nose-Hoover/ Parinello-Rahman with the paraeters below was stable for me with 238 POPC and 21524 water. integrator

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Justin Lemkul
On 8/16/12 10:21 PM, Mark Abraham wrote: On 17/08/2012 11:46 AM, Justin Lemkul wrote: On 8/16/12 9:43 PM, Jianguo Li wrote: What I think is that anisotropic coupling may be faster in equilibrium. Suppose the protein is quite different in x and y dimensions, after insertion, I think it is fa

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Peter C. Lai
You always use semi-isotropic for bilayer work. The Z is decoupled from x-y due to symmetry. I don't think I mention anything differently in the paper. Pcoupltype = semiisotropic On 2012-08-16 04:26:38PM -0700, Shima Arasteh wrote: > >  Hi, > > I have a question about the Prote

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Mark Abraham
On 17/08/2012 11:46 AM, Justin Lemkul wrote: On 8/16/12 9:43 PM, Jianguo Li wrote: What I think is that anisotropic coupling may be faster in equilibrium. Suppose the protein is quite different in x and y dimensions, after insertion, I think it is faster to get equilibrium the box length sepa

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Justin Lemkul
On 8/16/12 9:43 PM, Jianguo Li wrote: What I think is that anisotropic coupling may be faster in equilibrium. Suppose the protein is quite different in x and y dimensions, after insertion, I think it is faster to get equilibrium the box length separately. I agree with you that semi-isotropic c

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Jianguo Li
What I think is that anisotropic coupling may be faster in equilibrium. Suppose the protein is quite different in x and y dimensions, after  insertion, I think it is faster to get equilibrium the box length separately. I agree with you that semi-isotropic coupling in the first step can also do

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Justin Lemkul
On 8/16/12 9:14 PM, Jianguo Li wrote: After inserting the protein, the equilibrium box length in the x and y dimension should be different, so you need anisotropic pressure coupling during the 1st step. After equilibrium, the ratio of box length in x,y is fixed, so you can use semi-isotropic

Re: [gmx-users] Protein-POPC bilayer

2012-08-16 Thread Jianguo Li
After inserting the protein, the equilibrium box length in the x and y dimension should be different, so you need anisotropic pressure coupling during the 1st step. After equilibrium, the ratio of box length in x,y is fixed, so you can use semi-isotropic method. --Jianguo ___

[gmx-users] Protein-POPC bilayer

2012-08-16 Thread Shima Arasteh
 Hi, I have a question about the Protein-POPC system: To insert a protein in lipid bilayer, I am suggested to simulate POPC in water separately before insertion, it might decrease the time of final simulation. It's OK! In the article suggested me by dear Peter C. Lai, I read that POPC was sim

Re: [gmx-users] atom numbering

2012-08-16 Thread Justin Lemkul
On 8/16/12 5:22 PM, dariush wrote: Dear All, I have bilayer system plus two proteins in my system. I numbered residues manually, but after minimization number of residues for both protein 1 and 2 starts from 1. It means in VMD when I am going to pick res. 3 (resid 3), it will highlight two res

[gmx-users] atom numbering

2012-08-16 Thread dariush
Dear All, I have bilayer system plus two proteins in my system. I numbered residues manually, but after minimization number of residues for both protein 1 and 2 starts from 1. It means in VMD when I am going to pick res. 3 (resid 3), it will highlight two res. 3, one in protein 1 and one in protei

Re: [gmx-users] Re: RMSF error when fitting to average structure

2012-08-16 Thread Justin Lemkul
On 8/16/12 4:19 PM, tdgrant1 wrote: No they do not. The trajectory contains all the atoms, including the solvent (~300,000 atoms), whereas the structure passed to -s is the averaged structure from the last 60ns of simulation and only includes the non-solvent atoms (~15,000). Should I rerun rm

[gmx-users] Re: RMSF error when fitting to average structure

2012-08-16 Thread tdgrant1
No they do not. The trajectory contains all the atoms, including the solvent (~300,000 atoms), whereas the structure passed to -s is the averaged structure from the last 60ns of simulation and only includes the non-solvent atoms (~15,000). Should I rerun rmsf on the last 60ns but select System in

Re: [gmx-users] Re: RMSF error when fitting to average structure

2012-08-16 Thread Justin Lemkul
On 8/16/12 4:11 PM, tdgrant1 wrote: This "System" as described by group 0 in the previous message is actually only the solute, a protein-tRNA complex of ~15000 atoms. I tried running only the backbone and even only c-alphas (808 atoms total) and I still received a segmentation fault. Do the

[gmx-users] Re: RMSF error when fitting to average structure

2012-08-16 Thread tdgrant1
This "System" as described by group 0 in the previous message is actually only the solute, a protein-tRNA complex of ~15000 atoms. I tried running only the backbone and even only c-alphas (808 atoms total) and I still received a segmentation fault. -- View this message in context: http://groma

Re: [gmx-users] Re: RMSF error when fitting to average structure

2012-08-16 Thread Justin Lemkul
On 8/16/12 3:54 PM, tdgrant1 wrote: Oh okay, thanks. I didn't realize warnings were just that, only warnings and didn't stop the program. The program did not finish however, and the problem was a Segmentation Fault. The output literally was: Select a group: 0 Selected 0: 'System' Reading fr

[gmx-users] Re: RMSF error when fitting to average structure

2012-08-16 Thread tdgrant1
Oh okay, thanks. I didn't realize warnings were just that, only warnings and didn't stop the program. The program did not finish however, and the problem was a Segmentation Fault. The output literally was: Select a group: 0 Selected 0: 'System' Reading frame 0 time0.000 WARNING: if

Re: [gmx-users] Re: RMSF error when fitting to average structure

2012-08-16 Thread Justin Lemkul
On 8/16/12 3:19 PM, tdgrant1 wrote: Hi Justin, I did indeed correct for periodic boundary conditions prior to running rmsf, so I'm not sure what the problem would be there. The message you got was a warning, not an error. The warning is generic and is printed by any Gromacs program that d

[gmx-users] Re: RMSF error when fitting to average structure

2012-08-16 Thread tdgrant1
Hi Justin, I did indeed correct for periodic boundary conditions prior to running rmsf, so I'm not sure what the problem would be there. Is there any way of producing an average structure from rmsf (or any other program for that matter) that is not output as a .pdb file but as a .tpr file? T

Re: [gmx-users] Ca ion simulation incorporated in protein structure

2012-08-16 Thread Justin Lemkul
On 8/16/12 2:45 PM, ram bio wrote: Dear Gromacs Users, I am trying to simulate a modeled protein -ligand complex in lipid bilayer using Gromacs 4.5.4 with Charmm27 FF. For my project purpose which is to see the effect of substitution of ions (Ca instead of Na ions) in the protein structure on

[gmx-users] Ca ion simulation incorporated in protein structure

2012-08-16 Thread ram bio
Dear Gromacs Users, I am trying to simulate a modeled protein -ligand complex in lipid bilayer using Gromacs 4.5.4 with Charmm27 FF. For my project purpose which is to see the effect of substitution of ions (Ca instead of Na ions) in the protein structure on protein ligand interactions , I have m

Re: [gmx-users] simmulated annealing excess temperature........................

2012-08-16 Thread tarak karmakar
Thanks a lot for the quick reply...probably I have overlooked this point earlier ..now I'm getting it properly On Thu, Aug 16, 2012 at 10:33 PM, Justin Lemkul wrote: > > > On 8/16/12 12:57 PM, tarak karmakar wrote: >> >> Dear All, >> >> In my simulation I want the

Re: [gmx-users] simmulated annealing excess temperature........................

2012-08-16 Thread Justin Lemkul
On 8/16/12 12:57 PM, tarak karmakar wrote: Dear All, In my simulation I want the temperature of the system to be reached at 300 K only after 3 ps. But after 3ps I see temperature became 402 K. So am I doing any mistake in the '.mdp' file given below? You have a few. 1. You should not run M

Re: [gmx-users] RMSF error when fitting to average structure

2012-08-16 Thread Justin Lemkul
On 8/16/12 10:13 AM, tdgrant1 wrote: Dear all, I have a 70 ns trajectory for which the last 60 ns appears to be equilibrated. I'm attempting to create a plot of RMSF but I want to align it to the equilibrated structure, not the starting structure. I first ran g_rmsf using the starting struct

[gmx-users] simmulated annealing excess temperature........................

2012-08-16 Thread tarak karmakar
Dear All, In my simulation I want the temperature of the system to be reached at 300 K only after 3 ps. But after 3ps I see temperature became 402 K. So am I doing any mistake in the '.mdp' file given below? define= -DFLEXIBLE constraints= h-bonds integrator = sd

[gmx-users] RMSF error when fitting to average structure

2012-08-16 Thread tdgrant1
Dear all, I have a 70 ns trajectory for which the last 60 ns appears to be equilibrated. I'm attempting to create a plot of RMSF but I want to align it to the equilibrated structure, not the starting structure. I first ran g_rmsf using the starting structure as the reference structure over only

[gmx-users] About Number of Components of eigen Vector

2012-08-16 Thread vidhya sankar
Dear justin Thank you for your gem of Reply  I am doing ED. With respect to my all  900 C-alpha atoms So I have used the output of g_covar namely eigvec.trr  as input to g_anaeig_d  as follows g_anaeig_d  -v eigenvec.trr -comp eig1.xvg -first 1 -last 3 -xvg none I have obtained eig1.xvg  i

Re: [gmx-users] box vectors - regd

2012-08-16 Thread ramesh cheerla
Dear Mark, Once again I am very thankful to you for your reply, I have extracted box vectors from .XTC file by using g_traj with -ob option with this I was able to get only six vector components viz XX YY ZZ YX ZX and ZY only how about remaining three vector components XY XZ a

Re: [gmx-users] Ordering of hydrogen bonds in -hbn and -hbm output in g_hbond

2012-08-16 Thread Erik Marklund
Hi, I think the confusion arises from how the xpm data is displayed. If you have the hb-index on the y-axis in a plot with the positive y-direction pointing upwards (as in most plots), then the first line in the xpm file is actually displayed at the bottom. For matrices, however, the indexing s

Re: [gmx-users] Ordering of hydrogen bonds in -hbn and -hbm output in g_hbond

2012-08-16 Thread Erik Marklund
I think the confusion arises form 15 aug 2012 kl. 22.53 skrev Justin Lemkul: > > > On 8/15/12 4:49 PM, Andrew DeYoung wrote: >> Hi, >> >> I am a novice user of g_hbond (actually, I am using double precision -- >> g_hbond_d -- but I think all of the parameters should be the same). >> >> I woul

[gmx-users] RE: RE: RE: Doubts over g_lie usage

2012-08-16 Thread J Peterson
Thank you so much for your time and explanation. I am recalculating the energy co-ordinates and using it in g_lie calculations. I have read the manual and changed the .mdp file I am using. The following is the mdp file, please check for the correctness. The text in bold font are newly included af

Re: [gmx-users] CHARMM36 - Smaller Area per lipid for POPE - Why?

2012-08-16 Thread Felipe Pineda, PhD
Hi Sébastian, I think the "magic word" in this issue would be surface tension and the proper ensemble for the simulation NPgammaT. This is very well discussed in the paper I advised to you a couple of days ago. The issue is by no means trivial, although I'm not an expert to judge it. You can f

Re: [gmx-users] Questions regarding Polarization Energy Calculation

2012-08-16 Thread Mark Abraham
On 16/08/2012 5:08 PM, jesmin jahan wrote: Hi Mark, Thanks for your reply. If I open the .tpr file using notepad, it seems to be a binary file. Then, how to remove the the bonded terms and zero the VDW parameters? In the .top file from which you made the .tpr. (And contributing .itp files) P

Re: [gmx-users] Questions regarding Polarization Energy Calculation

2012-08-16 Thread jesmin jahan
Hi Mark, Thanks for your reply. If I open the .tpr file using notepad, it seems to be a binary file. Then, how to remove the the bonded terms and zero the VDW parameters? I really need to compare how fast different well known package can compute GB-polarization energy and how good the energy val