[gmx-users] Gromacs versions 4.0.5 and 4.5.4

Sapna Sarupria sapna.sarupria at gmail.com
Wed Oct 19 23:40:56 CEST 2011


Hello,

I did change nsttcouple and nstpcouple but the simulations that run in 4.0.5
are still crashing in 4.5.4. I think it is related to constraints but I am
unable to figure out exactly what is different. I have pasted both my
topology and mdp (updated for 4.5.4) files. Any ideas? I have read through
the manual and it seems like the mdp files does not need any changes, but
perhaps I am missing something.

Thank you for your help!

Sincerely,
Sapna

@@@@ MDP File @@@@
title               =  100% occupancy CO2 hydrate ; a string
cpp               =  /lib/cpp                 ; c-preprocessor
integrator        = md
dt                  =  0.002                    ; time step
nsteps           =  15000000                 ; number of steps
nstcomm       =  10                       ; reset c.o.m. motion
nstxout           =  0000                    ; write coords
nstvout           =  0000                    ; write velocities
nstlog             =  25000                    ; print to logfile
nstenergy       =  500                      ; print energies
xtc_grps         =  OW_HW1_HW2_CO2
nstxtcout        =  1000
nstlist             =  10                       ; update pairlist
ns_type            =  grid                     ; pairlist method
coulombtype    =  PME
rvdw                =  1.2                      ; cut-off for vdw
rcoulomb         =  1.2                      ; cut-off for coulomb
rlist                  =  1.2                      ; cut-off for coulomb
DispCorr         =  EnerPres
Tcoupl             =  Nose-Hoover
ref_t                 = 270
tc-grps             =  System
tau_t                 =  0.5
nsttcouple          =  1
Pcoupl              =  Parrinello-Rahman
Pcoupltype        =  semiisotropic            ; pressure geometry
tau_p                  =  1.0   1.0                ; p-coupoling time
compressibility   =  4.5e-5  4.5e-5           ; compressibility
ref_p                   =  30.5  30.5               ; ref pressure
nstpcouple          =  1
gen_vel               =  yes                      ; generate initial vel
gen_temp            =  260                      ; initial temperature
gen_seed             =  372340                   ; random seed
constraint_algorithm = shake
constraints         =  all-bonds
@@@@ end MDP File @@@@

@@@@ Topology file @@@@

[ defaults ]
; nbfunc        comb-rule       gen-pairs       fudgeLJ fudgeQQ
  1             2               no              1.0     1.0

[ atomtypes ]
; name      mass      charge    ptype         sigma       epsilon
; Water parameters are those of Vega TIP4P/Ice Model
 OWT4     15.9994      0.0000    A          0.31668     0.882164429
  HW        1.008          0.5897    A          0.000       0.000
  MW        0.000         -1.1794    V          0.000       0.000


; TraPPE  rigid
  M2      22.0000       0.00      A          0.000      0.000000 ;
  M1      22.0000       0.00      A          0.000      0.000000 ;
  DO      00.0000      -0.35      V          0.305      0.656806 ; oxygen
  DC      00.0000       0.70      V    0.280      0.224478 ; carbon


[ moleculetype ]
; molname  nrexcl
  SOL       2

[ atoms ]
1       OWT4      1      SOL      OW     1       0.0000
2         HW      1       SOL     HW1     1       0.5897
3         HW      1       SOL     HW2     1       0.5897
4         MW      1       SOL      MW     1      -1.1794

[ bonds ]
; i j funct length force.c.
1 2 1   0.09572     502416.0
1 3 1        0.09572     502416.0
2       3       1       0.15139     502416.0

[ exclusions ]
1    2    3     4
2    1    3     4
3    1    2     4
4    1    2     3

; The position of the dummy is computed as follows:
;
; O
;
;     D
;
; H H
;
; const = distance (OD) / [ cos (angle(DOH)) * distance (OH) ]
;  0.01577 nm / [ cos (52.26 deg) * 0.09572 nm ]

; Dummy pos x4 = x1 + a*(x2-x1) + b*(x3-x1)

[ virtual_sites3 ]
; Dummy from funct a b
4 1 2 3 1 0.13458335087   0.13458335087

[ moleculetype ]
; molname  nrexcl
  TIP       2

[ atoms ]
1       OWT4      1     TIP      OW     1       0.0000
2         HW      1       TIP     HW1     1       0.5897
3         HW      1       TIP     HW2     1       0.5897
4         MW      1       TIP      MW     1      -1.1794

[ bonds ]
; i j funct length force.c.
1 2 1   0.09572     502416.0
1 3 1        0.09572     502416.0
2       3       1       0.15139     502416.0

[ exclusions ]
1    2    3     4
2    1    3     4
3    1    2     4
4    1    2     3

[ virtual_sites3 ]
; Dummy from funct a b
4 1 2 3 1 0.13458335087   0.13458335087


[ moleculetype ]
; molname  nrexcl
  CO2    2

[ atoms ]
1         M1      1       CO2      M1      1       0.00    22.00
2         M2      1       CO2      M2      1       0.00    22.00
3         DC      1       CO2      CO      1       0.70    0.000
4         DO      1       CO2      OC1     1      -0.35    0.000
5         DO      1       CO2      OC2     1      -0.35    0.000


[ constraints ]
1    2      1    0.19785026


[ virtual_sites2 ]
; ai     aj     ak    funct    a
  3      1      2     1       0.50
  4      1      2     1      -0.086327900
  5      1      2     1       1.086327913

[ exclusions ]
3       4       5
4       5       3
5       4       3

[ system ]
Hydrate with cages filled with carbon dioxide

[ molecules ]
SOL    2944
CO2    512
TIP    3641

@@@@ End topology file @@@@




On Wed, Oct 19, 2011 at 7:17 AM, Sapna Sarupria <sapna.sarupria at gmail.com>wrote:

> Dear Itamar and Justin,
>
> Thank you for your responses. I will make the changes to the mdp files and
> see how easy or hard it is to make the shift from 4.0.5 to 4.5.
>
> Sincerely,
> Sapna
>
>
> On Tue, Oct 18, 2011 at 10:28 PM, Justin A. Lemkul <jalemkul at vt.edu>wrote:
>
>>
>>
>> Itamar Kass wrote:
>>
>>> Hi Sapna,
>>>
>>> It is a good question, but such of personal preferences.  I found out
>>> that my simulations tend to crash more often when I am using 4.5.5. It might
>>> be the General-reaction -field I use or something else, I am not sure. Also,
>>> it seems I will not gain much from upgrading, so I stick to 4.0.7.
>>>
>>>
>> The general instabilities result from tweaks to the handling of
>> temperature and pressure coupling.  Simply setting nsttcouple and nstpcouple
>> to 1 during the initial equilibration seems to give stable systems.
>>
>> I'd say there are many reasons for upgrading.  Tons of new features, bug
>> fixes, etc.  But then too, that's my personal preference ;)
>>
>> -Justin
>>
>>  All this is not to say that 4.5.5 is not a good simulation package. It is
>>> a good and useful MD package, and I highly appreciate all the time and
>>> effort put into it.
>>>
>>> Best,
>>> Itamat
>>>
>>> PS, there are still people around using 3.3.3 or even 3.2.1, so I am not
>>> that behind.
>>> On 19/10/2011, at 1:14 PM, Sapna Sarupria wrote:
>>>
>>>  Dear Itamar,
>>>>
>>>> Thank you for your response. Why did you prefer to stick to 4.0.7? Is
>>>> there something particularly difficult to transfer from 4.0.7 version to 4.5
>>>> version?
>>>>
>>>> Sapna
>>>>
>>>> On Tue, Oct 18, 2011 at 9:36 PM, Itamar Kass <itamar.kass at monash.edu<mailto:
>>>> itamar.kass at monash.edu**>> wrote:
>>>>
>>>>    Hi Sapna,
>>>>
>>>>    I had the same problem few weeks ago.
>>>>
>>>>    Apparently, some parameters are different (eg. nstpcouple).
>>>>
>>>>    Cheers,
>>>>    Itamar
>>>>
>>>>    PS I found out that I prefer to stick to 4.0.7.
>>>>
>>>>
>>>>
>>>>
>>>>    On 19/10/2011, at 12:08 PM, Sapna Sarupria wrote:
>>>>
>>>>     Dear All,
>>>>>
>>>>>    I have a simulation set up for a mixture of carbon dioxide and
>>>>>    water system which runs perfectly on Gromacs 4.0.5 version. I
>>>>>    have run these simulations at different temperatures and
>>>>>    pressures, from the same starting configuration and the
>>>>>    simulation proceeds smoothly in the 4.0.5 version. However, when
>>>>>    I use exactly the same files to run the simulation in 4.5.4
>>>>>    version, the system crashes and writes out several pdb files. I
>>>>>    was wondering if there is anything specific that has been changed
>>>>>    between the two versions. I have pasted the mdp file of the
>>>>>    simulations below. Any input will be much appreciated.
>>>>>
>>>>>    MDP File
>>>>>    title               =  100% occupancy CO2 hydrate ; a string
>>>>>    cpp               =  /lib/cpp                 ; c-preprocessor
>>>>>    dt                  =  0.002                    ; time step
>>>>>    nsteps          =  15000000                 ; number of steps
>>>>>    nstcomm      =  10                       ; reset c.o.m. motion
>>>>>    nstxout          =  0000                    ; write coords
>>>>>    nstvout          =  0000                    ; write velocities
>>>>>    nstlog             =  25000                    ; print to logfile
>>>>>    nstenergy       =  500                      ; print energies
>>>>>    xtc_grps          =  OW_HW1_HW2_CO2     nstxtcout         =  1000
>>>>>    nstlist               =  10                       ; update pairlist
>>>>>    ns_type            =  grid                     ; pairlist method
>>>>>    coulombtype    =  PME
>>>>>    rvdw                  =  1.2                      ; cut-off for vdw
>>>>>    rcoulomb          =  1.2                      ; cut-off for coulomb
>>>>>    rlist                    =  1.2                      ; cut-off
>>>>>    for coulomb
>>>>>    DispCorr          =  EnerPres
>>>>>    Tcoupl              =  Nose-Hoover
>>>>>    ref_t                  = 270     tc-grps              =  System
>>>>>    tau_t                 =  0.5     Pcoupl             =
>>>>>  Parrinello-Rahman
>>>>>    Pcoupltype      =  semiisotropic            ; pressure geometry
>>>>>    tau_p                =  1.0   1.0                ; p-coupoling time
>>>>>    compressibility   =  4.5e-5  4.5e-5           ; compressibility
>>>>>    ref_p                     =  30.5  30.5               ; ref pressure
>>>>>    gen_vel               =  yes                      ; generate
>>>>>    initial vel
>>>>>    gen_temp             =  260                      ; initial
>>>>>    temperature
>>>>>    gen_seed             =  372340                   ; random seed
>>>>>    constraint_algorithm = shake
>>>>>    constraints         =  all-bonds
>>>>>    -------
>>>>>
>>>>>
>>>>>    Thank you,
>>>>>
>>>>>    Sincerely,
>>>>>    Sapna
>>>>>    --     gmx-users mailing list    gmx-users at gromacs.org
>>>>>    <mailto:gmx-users at gromacs.org>
>>>>>
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>>>>> >.
>>>>>
>>>>>    Can't post? Read http://www.gromacs.org/**Support/Mailing_Lists<http://www.gromacs.org/Support/Mailing_Lists>
>>>>>
>>>>
>>>>    -----
>>>>    "In theory, there is no difference between theory and practice.
>>>>    But, in practice, there is." - Jan L.A. van de Snepscheut
>>>>
>>>>    ==============================**=============
>>>>    | Itamar Kass, Ph.D.
>>>>    | Postdoctoral Research Fellow
>>>>    |
>>>>    | Department of Biochemistry and Molecular Biology
>>>>    | Building 77 Clayton Campus
>>>>    | Wellington Road
>>>>    | Monash University,
>>>>    | Victoria 3800
>>>>    | Australia
>>>>    |
>>>>    | Tel: +61 3 9902 9376 <tel:%2B61%203%209902%209376>
>>>>    | Fax: +61 3 9902 9500 <tel:%2B61%203%209902%209500>
>>>>    | E-mail: Itamar.Kass at monash.edu <mailto:Itamar.Kass at monash.edu**>
>>>>
>>>>    ==============================**==============
>>>>
>>>>
>>>>    --
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>>>>
>>>
>>> -----
>>> "In theory, there is no difference between theory and practice. But, in
>>> practice, there is." - Jan L.A. van de Snepscheut
>>>
>>> ==============================**=============
>>> | Itamar Kass, Ph.D.
>>> | Postdoctoral Research Fellow
>>> |
>>> | Department of Biochemistry and Molecular Biology
>>> | Building 77 Clayton Campus
>>> | Wellington Road
>>> | Monash University,
>>> | Victoria 3800
>>> | Australia
>>> |
>>> | Tel: +61 3 9902 9376
>>> | Fax: +61 3 9902 9500
>>> | E-mail: Itamar.Kass at monash.edu <mailto:Itamar.Kass at monash.edu**>
>>> ==============================**==============
>>>
>>>
>> --
>> ==============================**==========
>>
>> 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<http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin>
>>
>> ==============================**==========
>>
>> --
>>
>


-- 
Sapna Sarupria
Post-doctoral Researcher
Princeton University
New Jersey 08540
U.S.A.

Life isn't about finding yourself. Life is about creating yourself. --
George Bernard Shaw.
Dare to Dream
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