[gmx-users] Segmentation Fault - Water on Substrate

Diez Fernandez, Amanda amanda.diez10 at imperial.ac.uk
Sun Jun 26 16:03:14 CEST 2016


Hi Mark, 
Thanks for your quick response.

In the all three minimisation.mdp files (the one for water.pdb,
substrate.pdb and merged.pdb) I have:

pbc                     = xyz

To minimise the water.pdb file I have:

periodic_molecules = no ;


To minimise the substrate.pdb and then the merged.pdb I have:

periodic_molecules = yes ;


Is this what you meant?
When I minimise substrate.pdb or water.pdb alone it works. When I combine
them and minimise merged.pdb it doesn¹t.

Cheers,
Amanda



>------------------------------
>
>Message: 5
>Date: Sun, 26 Jun 2016 09:53:46 +0000
>From: Mark Abraham <mark.j.abraham at gmail.com>
>To: gmx-users at gromacs.org, "gromacs.org_gmx-users at maillist.sys.kth.se"
>	<gromacs.org_gmx-users at maillist.sys.kth.se>
>Subject: Re: [gmx-users] Segmentation Fault - Water on Substrate
>Message-ID:
>	<CAMNuMAT12F5AdcFP8rQ3CvfT21vyveqKbDt0LYkRnWwLgrGzVA at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>Hi,
>
>You're presumably making one of your formerly periodic dimensions
>differently periodic when you combine your boxes. If your input structure
>has molecules with coordinates that are broken across the former boundary,
>you need to make them whole before your merge can work sanely.
>
>Mark
>
>On Sun, Jun 26, 2016 at 11:45 AM Diez Fernandez, Amanda <
>amanda.diez10 at imperial.ac.uk> wrote:
>
>> Dear Gromacs users,
>>
>> I am want to simulate water on a  substrate.
>> I have a water.pdb file with the coordinates of a cuboid of water and a
>> substrate.pdb file with the coordinates of the substrate. The box
>> dimensions along the x and y directions are identical for both  files.
>> I run two simulations to minimise both structures separately. I get no
>> error, meaning the topology file must be correct (is this a correct
>> assumption?) This also ensures that all atoms in the minimised.pdb files
>> are within the box I have specified  (as opposed to before, when some
>>atoms
>> were slightly outside).
>> I then have a script to merge both minimised .pdb files.
>> I minimise the system and get a segmentation fault:
>>
>> 40783 Segmentation fault
>>
>> Further, in the file.log I get:
>>
>>
>> Steepest Descents:
>>
>>    Tolerance (Fmax)   =  6.00000e+01
>>
>>    Number of steps    =       100000
>>
>>            Step           Time         Lambda
>>
>>               0        0.00000        0.00000
>>
>>
>>    Energies (kJ/mol)
>>
>>            Bond          Angle          LJ-14     Coulomb-14        LJ
>>(SR)
>>
>>     1.36501e+04    6.58753e+04    4.22206e+04   -1.70332e+06
>>-nan
>>
>>    Coulomb (SR)   Coul. recip.      Potential Pressure (bar)
>>
>>     1.18196e+06    2.65781e+03           -nan           -nan
>>
>>
>>
>> I have visualised the input merged.pdb file and have also checked the
>> minimum and maximum coordinates of water and substrate and I am sure
>>there
>> is no atom overlap. In fact, water and substrate atoms are separate by
>>more
>> than 3A.  ( I have also tried previously with smaller separations).
>>
>> What could else could I check?
>>
>> Thanks,
>> Amanda
>> --
>> Gromacs Users mailing list
>>
>> * Please search the archive at
>> http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before
>> posting!
>>
>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>
>> * For (un)subscribe requests visit
>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>> send a mail to gmx-users-request at gromacs.org.
>>
>
>
>------------------------------
>
>Message: 6
>Date: Sun, 26 Jun 2016 09:53:46 +0000
>From: Mark Abraham <mark.j.abraham at gmail.com>
>To: gmx-users at gromacs.org, "gromacs.org_gmx-users at maillist.sys.kth.se"
>	<gromacs.org_gmx-users at maillist.sys.kth.se>
>Subject: Re: [gmx-users] Segmentation Fault - Water on Substrate
>Message-ID:
>	<CAMNuMAT12F5AdcFP8rQ3CvfT21vyveqKbDt0LYkRnWwLgrGzVA at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>Hi,
>
>You're presumably making one of your formerly periodic dimensions
>differently periodic when you combine your boxes. If your input structure
>has molecules with coordinates that are broken across the former boundary,
>you need to make them whole before your merge can work sanely.
>
>Mark
>
>On Sun, Jun 26, 2016 at 11:45 AM Diez Fernandez, Amanda <
>amanda.diez10 at imperial.ac.uk> wrote:
>
>> Dear Gromacs users,
>>
>> I am want to simulate water on a  substrate.
>> I have a water.pdb file with the coordinates of a cuboid of water and a
>> substrate.pdb file with the coordinates of the substrate. The box
>> dimensions along the x and y directions are identical for both  files.
>> I run two simulations to minimise both structures separately. I get no
>> error, meaning the topology file must be correct (is this a correct
>> assumption?) This also ensures that all atoms in the minimised.pdb files
>> are within the box I have specified  (as opposed to before, when some
>>atoms
>> were slightly outside).
>> I then have a script to merge both minimised .pdb files.
>> I minimise the system and get a segmentation fault:
>>
>> 40783 Segmentation fault
>>
>> Further, in the file.log I get:
>>
>>
>> Steepest Descents:
>>
>>    Tolerance (Fmax)   =  6.00000e+01
>>
>>    Number of steps    =       100000
>>
>>            Step           Time         Lambda
>>
>>               0        0.00000        0.00000
>>
>>
>>    Energies (kJ/mol)
>>
>>            Bond          Angle          LJ-14     Coulomb-14        LJ
>>(SR)
>>
>>     1.36501e+04    6.58753e+04    4.22206e+04   -1.70332e+06
>>-nan
>>
>>    Coulomb (SR)   Coul. recip.      Potential Pressure (bar)
>>
>>     1.18196e+06    2.65781e+03           -nan           -nan
>>
>>
>>
>> I have visualised the input merged.pdb file and have also checked the
>> minimum and maximum coordinates of water and substrate and I am sure
>>there
>> is no atom overlap. In fact, water and substrate atoms are separate by
>>more
>> than 3A.  ( I have also tried previously with smaller separations).
>>
>> What could else could I check?
>>
>> Thanks,
>> Amanda
>> --
>> Gromacs Users mailing list
>>
>> * Please search the archive at
>> http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before
>> posting!
>>
>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>
>> * For (un)subscribe requests visit
>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>> send a mail to gmx-users-request at gromacs.org.
>>
>
>
>------------------------------
>
>-- 
>Gromacs Users mailing list
>
>* Please search the archive at
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>posting!
>
>* Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>
>* For (un)subscribe requests visit
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>
>End of gromacs.org_gmx-users Digest, Vol 146, Issue 142
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