[gmx-users] Re: change in the secondary structure after simulation

Thomas Piggot t.piggot at soton.ac.uk
Thu Jan 27 14:31:02 CET 2011


Hi Bharat,

If you have used the -deffnm option then the output gro will be called 
whatever name you used for the -deffnm option and not the default 
confout.gro.

Tom

Justin A. Lemkul wrote:
> 
> bharat gupta wrote:
>> I didn't gave any -c flag while md run .. and there is no confout.gro in
>> my folder .. I have attached the graph obtained after energy minimzation
> 
> I've never heard of such a thing.  mdrun produces several files automatically:
> traj.trr, ener.edr, md.log, and confout.gro.  The output configuration is always
> written.  If it wasn't, then something is preventing mdrun from writing this
> file (full disk, read/write permissions, etc).
> 
>> .. I want to ask why the graph is not coming like the one shown in the
>> tutorial .. I guess I asked that same question earlier also ?? ..  Here
>> is the details of energy minimization result
>>
> 
> The shape of the graph is nearly identical.  You converged to an acceptable
> energy and force, so what's the problem?
> 
> If you're following the tutorial's procedure with a different system, there is
> absolutely no reason to expect that one system will converge to the same
> potential energy as another.  They're fundamentally different.  Even if you are
> working with the same system, there can be differences in the final energy.  EM
> is just a procedure to optimize the orientation of the molecules in the system.
>   It may converge somewhat differently each time you do it.
> 
> -Justin
> 
>> Steepest Descents converged to Fmax < 1000 in 720 steps
>> Potential Energy  = -6.7970475e+05
>> Maximum force     =  9.5201904e+02 on atom 78
>> Norm of force     =  1.9553707e+01
>>
>>
>>
>>
>> On Thu, Jan 27, 2011 at 5:12 AM, Justin A. Lemkul <jalemkul at vt.edu
>> <mailto:jalemkul at vt.edu>> wrote:
>>
>>
>>
>>     bharat gupta wrote:
>>
>>         I don't think that there is any problem in the structure ..
>>         since I am simulating the crystal structure taken from PDB ...
>>         and I have checked the structure generated after pdb2gmx and
>>         solvation..
>>          Since I am reapeating the simulation again I want to know and I
>>         am on energy minimzation step I want to know .. how can I
>>         retrieve the structure after minimization ..
>>
>>
>>     The structure after minimization (or any process done by mdrun) is
>>     contained in whatever filename you passed to the -c flag.  If you
>>     haven't specified any name, it is confout.gro.
>>
>>     -Justin
>>
>>         On Thu, Jan 27, 2011 at 4:16 AM, Mark Abraham
>>         <Mark.Abraham at anu.edu.au <mailto:Mark.Abraham at anu.edu.au>
>>         <mailto:Mark.Abraham at anu.edu.au
>>         <mailto:Mark.Abraham at anu.edu.au>>> wrote:
>>
>>            On 27/01/2011 11:11 PM, bharat gupta wrote:
>>
>>                I used the same .mdp files that are given in the lysozyme
>>             tutorial
>>                .. Since I was knowing what all parameters to change ..
>>             but after
>>                energy minimization and equilibration steps , the graphs
>>             that I
>>                got were fine ... even the rmsd graph of the final
>>             structure is
>>                also fine .. I have attached the final rmsd graph of the
>>             structure ..
>>
>>
>>            That suggests the problem was in the structure you started the
>>            simulation from, like I've suggested a few times now :-)
>>
>>            Mark
>>
>>
>>
>>                On Thu, Jan 27, 2011 at 3:44 AM, Justin A. Lemkul
>>             <jalemkul at vt.edu <mailto:jalemkul at vt.edu>
>>                <mailto:jalemkul at vt.edu <mailto:jalemkul at vt.edu>>> wrote:
>>
>>
>>
>>                    bharat gupta wrote:
>>
>>                        I generated the secondary structure profile of
>>             structure
>>                        retrieved from the last frame of the simulation
>>             ... In
>>                        that profile those amino acids that are shown as
>>             loops in
>>                        VMD doesnot have any secondary structure
>>             assignment ... it
>>                        means that during simulation the structure got
>>             changed
>>                        some how ... and It's really surprising ?? ...
>>             Can u tell
>>                        me where can the fault be as I am planning to do the
>>                        simulation again and this time I will check the
>>             structure
>>                        after every step .. but for that I want to know
>>             how can I
>>                        save the structure after every step say for eg. after
>>                        energy minimization ..
>>
>>
>>                    Secondary structure is dependent upon the chosen
>>             force field
>>                    and the .mdp settings.  Since you've posted neither,
>>             there's
>>                    no way to tell what might be to blame.
>>
>>                    You can save more frequently by setting the proper output
>>                    controls.  Read in the manual about the nst* options
>>             and set
>>                    the accordingly.
>>
>>                    -Justin
>>
>>                        On Thu, Jan 27, 2011 at 8:35 PM, Justin A. Lemkul
>>                        <jalemkul at vt.edu <mailto:jalemkul at vt.edu>
>>             <mailto:jalemkul at vt.edu <mailto:jalemkul at vt.edu>>
>>                        <mailto:jalemkul at vt.edu <mailto:jalemkul at vt.edu>
>>             <mailto:jalemkul at vt.edu <mailto:jalemkul at vt.edu>>>> wrote:
>>
>>
>>
>>                           Mark Abraham wrote:
>>
>>
>>
>>                               On 01/27/11, *bharat gupta *
>>                        <bharat.85.monu at gmail.com
>>             <mailto:bharat.85.monu at gmail.com>
>>             <mailto:bharat.85.monu at gmail.com
>>             <mailto:bharat.85.monu at gmail.com>>
>>                               <mailto:bharat.85.monu at gmail.com
>>             <mailto:bharat.85.monu at gmail.com>
>>                        <mailto:bharat.85.monu at gmail.com
>>             <mailto:bharat.85.monu at gmail.com>>>> wrote:
>>
>>                                   I actually don't understand exactly
>>             what u are
>>                        asking ..
>>                                   since I am not an expert with gromacs..
>>
>>
>>                               Please leave the old context for the
>>             discussion in
>>                        future
>>                               emails. Only you are paying so much
>>             attention to
>>                        your work that
>>                               you can be sure of remembering things :-)
>>
>>                               If your simulation started with these strands
>>                        unfolded, then
>>                               your problem is somewhere else. However,
>>             you have
>>                        to be able to
>>                               tell us what was the initial conformation,
>>             and when
>>                        your "first
>>                               trajectory frame" (per last email)
>>             happened in the
>>                        simulation.
>>
>>
>>                           I would also add that VMD does a fairly poor job
>>                        sometimes of
>>                           guessing secondary structure.  So if no beta
>>             strand was
>>                        present in
>>                           the very first frame, that doesn't necessarily
>>             mean the
>>                        secondary
>>                           structure wasn't stable, it just means VMD didn't
>>                        display it properly.
>>
>>                           -Justin
>>
>>                               Mark
>>
>>
>>                                   I don't know when is was written ..
>>             Here are
>>                        some lines from
>>                                   the log files of simulation ...
>>                                   Statistics over 1500001 steps using
>>             300001 frames
>>
>>                                     Energies (kJ/mol)
>>                                            Angle    Proper Dih.
>>             Ryckaert-Bell.                     LJ-14
>>                                       Coulomb-14
>>                                      7.35090e+03    4.37413e+02
>>              3.60104e+03               5.26705e+03
>>                                      2.58894e+04
>>                                          LJ (SR)  Disper. corr.
>>             Coulomb (SR)              Coul. recip.
>>                                        Potential
>>                                      1.05399e+05   -2.92853e+03
>>             -6.79288e+05              -1.07015e+05
>>                                     -6.41286e+05
>>                                      Kinetic En.   Total Energy
>>              Temperature
>>                        Pres. DC (bar)
>>                                   Pressure (bar)
>>                                      1.03484e+05   -5.37802e+05
>>              3.00003e+02              -2.37485e+02
>>                                      1.02890e+00
>>                                     Constr. rmsd
>>                                      0.00000e+00
>>
>>                                            Box-X          Box-Y
>>              Box-Z
>>                                      7.42618e+00    7.42618e+00
>>              7.42618e+00
>>
>>                                     Total Virial (kJ/mol)
>>                                      3.44183e+04    3.40020e+01
>>             -1.17357e+01
>>                                      3.42160e+01    3.45369e+04
>>             -2.46337e+01
>>                                     -1.16644e+01   -2.48479e+01
>>              3.44949e+04
>>
>>                                     Pressure (bar)
>>                                      1.99809e+00    9.48448e-02
>>              4.57909e-01
>>                                      7.74354e-02    4.97824e-01
>>              1.84797e+00
>>                                      4.52125e-01    1.86535e+00
>>              5.90776e-01
>>
>>                                     Total Dipole (D)
>>                                     -1.86272e+02    4.46310e+01
>>              2.08554e+02
>>
>>                                        T-Protein  T-non-Protein
>>                                      2.99904e+02    3.00013e+02
>>
>>
>>                                   M E G A - F L O P S   A C C O U N T I N G
>>
>>
>>                                   There were in total 1502 frames (as
>>             shown in
>>                        VMD )...
>>                                   I don't know about how it compared
>>             with the
>>                        coordinates of
>>                                   the structure that I gave to grompp
>>
>>                                   --------
>>
>>                                   Pls guide
>>
>>
>>
>>
>>                                   --             Bharat
>>                                   Ph.D. Candidate
>>                                   Room No. : 7202A, 2nd Floor
>>                                   Biomolecular Engineering Laboratory
>>                                   Division of Chemical Engineering and
>>             Polymer
>>                        Science
>>                                   Pusan National University
>>                                   Busan -609735
>>                                   South Korea
>>                                   Lab phone no. - +82-51-510-3680,
>>             +82-51-583-8343
>>                                   Mobile no. - 010-5818-3680
>>                                   E-mail : monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>
>>                        <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>> <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>
>>                        <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>>>
>>                                   <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>
>>                        <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>> <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>
>>                        <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>>>>
>>
>>
>>
>>                           --     ========================================
>>
>>                           Justin A. Lemkul
>>                           Ph.D. Candidate
>>                           ICTAS Doctoral Scholar
>>                           MILES-IGERT Trainee
>>                           Department of Biochemistry
>>                           Virginia Tech
>>                           Blacksburg, VA
>>                           jalemkul[at]vt.edu <http://vt.edu/>
>>             <http://vt.edu/> <http://vt.edu <http://vt.edu/>
>>
>>                        <http://vt.edu/>> | (540) 231-9080
>>
>>
>>             http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin
>>
>>                           ========================================
>>                           --     gmx-users mailing list
>>              gmx-users at gromacs.org <mailto:gmx-users at gromacs.org>
>>                        <mailto:gmx-users at gromacs.org
>>             <mailto:gmx-users at gromacs.org>>
>>                           <mailto:gmx-users at gromacs.org
>>             <mailto:gmx-users at gromacs.org>
>>                        <mailto:gmx-users at gromacs.org
>>             <mailto:gmx-users at 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-request at gromacs.org
>>             <mailto:gmx-users-request at gromacs.org>
>>                        <mailto:gmx-users-request at gromacs.org
>>             <mailto:gmx-users-request at gromacs.org>>
>>                           <mailto:gmx-users-request at gromacs.org
>>             <mailto:gmx-users-request at gromacs.org>
>>                        <mailto:gmx-users-request at gromacs.org
>>             <mailto:gmx-users-request at gromacs.org>>>.
>>
>>                           Can't post? Read
>>                        http://www.gromacs.org/Support/Mailing_Lists
>>
>>
>>
>>
>>                        --             Bharat
>>                        Ph.D. Candidate
>>                        Room No. : 7202A, 2nd Floor
>>                        Biomolecular Engineering Laboratory
>>                        Division of Chemical Engineering and Polymer Science
>>                        Pusan National University
>>                        Busan -609735
>>                        South Korea
>>                        Lab phone no. - +82-51-510-3680, +82-51-583-8343
>>                        Mobile no. - 010-5818-3680
>>                        E-mail : monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com> <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>>
>>                        <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com> <mailto:monu46010 at yahoo.com
>>             <mailto:monu46010 at yahoo.com>>>
>>
>>
>>                    --         ========================================
>>
>>                    Justin A. Lemkul
>>                    Ph.D. Candidate
>>                    ICTAS Doctoral Scholar
>>                    MILES-IGERT Trainee
>>                    Department of Biochemistry
>>                    Virginia Tech
>>                    Blacksburg, VA
>>                    jalemkul[at]vt.edu <http://vt.edu/> <http://vt.edu/>
>>             | (540) 231-9080
>>                    http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin
>>
>>                    ========================================
>>                    --         gmx-users mailing list
>>              gmx-users at gromacs.org <mailto:gmx-users at gromacs.org>
>>                    <mailto:gmx-users at gromacs.org
>>             <mailto:gmx-users at 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-request at gromacs.org
>>             <mailto:gmx-users-request at gromacs.org>
>>                    <mailto:gmx-users-request at gromacs.org
>>             <mailto:gmx-users-request at gromacs.org>>.
>>                    Can't post? Read
>>             http://www.gromacs.org/Support/Mailing_Lists
>>
>>
>>
>>
>>                --     Bharat
>>                Ph.D. Candidate
>>                Room No. : 7202A, 2nd Floor
>>                Biomolecular Engineering Laboratory
>>                Division of Chemical Engineering and Polymer Science
>>                Pusan National University
>>                Busan -609735
>>                South Korea
>>                Lab phone no. - +82-51-510-3680, +82-51-583-8343
>>                Mobile no. - 010-5818-3680
>>                E-mail : monu46010 at yahoo.com <mailto:monu46010 at yahoo.com>
>>             <mailto:monu46010 at yahoo.com <mailto:monu46010 at yahoo.com>>
>>
>>
>>
>>            --
>>            gmx-users mailing list    gmx-users at gromacs.org
>>         <mailto:gmx-users at gromacs.org>
>>            <mailto:gmx-users at gromacs.org <mailto:gmx-users at 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-request at gromacs.org
>>         <mailto:gmx-users-request at gromacs.org>
>>            <mailto:gmx-users-request at gromacs.org
>>         <mailto:gmx-users-request at gromacs.org>>.
>>            Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>
>>
>>
>>
>>         --
>>         Bharat
>>         Ph.D. Candidate
>>         Room No. : 7202A, 2nd Floor
>>         Biomolecular Engineering Laboratory
>>         Division of Chemical Engineering and Polymer Science
>>         Pusan National University
>>         Busan -609735
>>         South Korea
>>         Lab phone no. - +82-51-510-3680, +82-51-583-8343
>>         Mobile no. - 010-5818-3680
>>         E-mail : monu46010 at yahoo.com <mailto:monu46010 at yahoo.com>
>>         <mailto:monu46010 at yahoo.com <mailto:monu46010 at yahoo.com>>
>>
>>
>>     --
>>     ========================================
>>
>>     Justin A. Lemkul
>>     Ph.D. Candidate
>>     ICTAS Doctoral Scholar
>>     MILES-IGERT Trainee
>>     Department of Biochemistry
>>     Virginia Tech
>>     Blacksburg, VA
>>     jalemkul[at]vt.edu <http://vt.edu/> | (540) 231-9080
>>     http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin
>>
>>     ========================================
>>     --
>>     gmx-users mailing list    gmx-users at gromacs.org
>>     <mailto:gmx-users at 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-request at gromacs.org
>>     <mailto:gmx-users-request at gromacs.org>.
>>     Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>
>>
>>
>>
>> --
>> Bharat
>> Ph.D. Candidate
>> Room No. : 7202A, 2nd Floor
>> Biomolecular Engineering Laboratory
>> Division of Chemical Engineering and Polymer Science
>> Pusan National University
>> Busan -609735
>> South Korea
>> Lab phone no. - +82-51-510-3680, +82-51-583-8343
>> Mobile no. - 010-5818-3680
>> E-mail : monu46010 at yahoo.com <mailto:monu46010 at yahoo.com>
>>
>>
>> ------------------------------------------------------------------------
>>
> 
> --
> ========================================
> 
> 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
> 
> ========================================
> --
> gmx-users mailing list    gmx-users at 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-request at gromacs.org.
> Can't post? Read http://www.gromacs.org/Support/Mailing_Lists

-- 
Dr Thomas Piggot
University of Southampton, UK.



More information about the gromacs.org_gmx-users mailing list