[gmx-users] how to simulate crystals in Gromacs

Mark Abraham Mark.Abraham at anu.edu.au
Thu Apr 7 09:25:19 CEST 2011


On 7/04/2011 4:21 PM, ZHANG Lu wrote:
> Thank you for your answer.
> Could you give me some advice on the size of cell box? What is the proper
> size if I want to do MD simulation in crystal environment?
> I didn't change the cell size when I convert cif file to pdb file; in
> other word, I didn't use editconf to produce the cell box. What I did was
> just :
> pdb2gmx -> genconf ( -nbox 10 10 10 -dist 0.5 0.5 0.5 ) -> genbox. Was it
> wrong?

I don't know. When you opened it in a visualization program and saw the
periodic box, and turned on the "show periodic images" option, did it
look reasonable?

Mark

> Below is the coordination and cell box after I run pdb2gmx. I use water to
> fill in the box after genconf.
>
>     1CLC    OBD    1  -0.042   0.476   0.219
>     1CLC    O1D    2  -0.298   0.731   0.310
>     1CLC    O2D    3  -0.163   0.650   0.469
>     1CLC    O1A    4  -0.697   0.691   0.093
>     1CLC    O2A    5  -0.822   0.826   0.214
>     1CLC    CMB    6  -0.877   0.164   0.937
>     1CLC    CAB    7  -0.708  -0.089   1.050
>     1CLC    CBB    8  -0.820  -0.108   1.104
>     1CLC    CMC    9  -0.224  -0.302   0.948
>     1CLC    CAC   10   0.016  -0.236   0.743
>     1CLC    CBC   11   0.014  -0.333   0.627
>     1CLC    CMD   12   0.106   0.164   0.377
>     1CLC    CAD   13  -0.122   0.426   0.298
>     1CLC    CBD   14  -0.260   0.494   0.322
>     1CLC    CAA   15  -0.598   0.558   0.332
>     1CLC    CBA   16  -0.685   0.684   0.330
>     1CLC    CMA   17  -0.672   0.604   0.686
>     1CLC    CGD   18  -0.246   0.640   0.366
>     1CLC    CED   19  -0.149   0.789   0.509
>     1CLC    CGA   20  -0.733   0.732   0.198
>     1CLC     C1   21  -0.878   0.885   0.095
>     1CLC    CMG   22  -0.373   0.175   0.683
>     1CLC     NB   23  -0.540   0.110   0.783
>     1CLC     NC   24  -0.278  -0.005   0.729
>     1CLC     ND   25  -0.234   0.194   0.534
>     1CLC     NA   26  -0.492   0.328   0.583
>     1CLC    C1B   27  -0.657   0.181   0.798
>     1CLC    C2B   28  -0.741   0.114   0.897
>     1CLC    C3B   29  -0.670   0.008   0.944
>     1CLC    C4B   30  -0.543   0.006   0.871
>     1CLC    CHC   31  -0.442  -0.086   0.890
>     1CLC    C1C   32  -0.317  -0.091   0.824
>     1CLC    C2C   33  -0.214  -0.193   0.847
>     1CLC    C3C   34  -0.112  -0.163   0.760
>     1CLC    C4C   35  -0.154  -0.045   0.688
>     1CLC    CHD   36  -0.078   0.019   0.591
>     1CLC    C1D   37  -0.112   0.131   0.520
>     1CLC    C2D   38  -0.033   0.201   0.421
>     1CLC    C3D   39  -0.115   0.309   0.380
>     1CLC    C4D   40  -0.234   0.301   0.455
>     1CLC    CHA   41  -0.325   0.405   0.430
>     1CLC    C1A   42  -0.448   0.417   0.491
>     1CLC    C2A   43  -0.545   0.533   0.476
>     1CLC    C3A   44  -0.657   0.499   0.577
>     1CLC    C4A   45  -0.612   0.366   0.634
>     1CLC    CHB   46  -0.687   0.294   0.727
>     1CLC   HMB1   47  -0.919   0.099   1.010
>     1CLC   HMB2   48  -0.868   0.263   0.978
>     1CLC   HMB3   49  -0.941   0.167   0.851
>     1CLC    HAB   50  -0.629  -0.151   1.086
>     1CLC   HBB1   51  -0.831  -0.182   1.180
>     1CLC   HBB2   52  -0.905  -0.049   1.074
>     1CLC   HMC1   53  -0.317  -0.294   1.000
>     1CLC   HMC2   54  -0.143  -0.294   1.018
>     1CLC   HMC3   55  -0.219  -0.397   0.899
>     1CLC   HAC1   56   0.029  -0.295   0.831
>     1CLC   HAC2   57   0.089  -0.162   0.718
>     1CLC   HBC1   58   0.108  -0.382   0.619
>     1CLC   HBC2   59  -0.063  -0.406   0.643
>     1CLC   HBC3   60  -0.006  -0.280   0.536
>     1CLC   HMD1   61   0.139   0.078   0.430
>     1CLC   HMD2   62   0.172   0.246   0.397
>     1CLC   HMD3   63   0.106   0.144   0.272
>     1CLC    HBD   64  -0.320   0.500   0.234
>     1CLC   HAA1   65  -0.661   0.476   0.307
>     1CLC   HAA2   66  -0.512   0.580   0.271
>     1CLC   HBA1   67  -0.774   0.656   0.383
>     1CLC   HBA2   68  -0.622   0.762   0.367
>     1CLC   HMA1   69  -0.751   0.575   0.753
>     1CLC   HMA2   70  -0.580   0.612   0.740
>     1CLC   HMA3   71  -0.696   0.698   0.642
>     1CLC   HED1   72  -0.082   0.795   0.592
>     1CLC   HED2   73  -0.245   0.827   0.538
>     1CLC   HED3   74  -0.111   0.846   0.427
>     1CLC    H11   75  -0.949   0.960   0.123
>     1CLC    H12   76  -0.927   0.809   0.037
>     1CLC    H13   77  -0.799   0.929   0.037
>     1CLC    HHC   78  -0.460  -0.161   0.963
>     1CLC    HHD   79   0.018  -0.024   0.570
>     1CLC    H2A   80  -0.497   0.626   0.495
>     1CLC    H3A   81  -0.754   0.495   0.531
>     1CLC    HHB   82  -0.785   0.334   0.746
>    0.87600   2.58600   0.73936   0.00000   0.00000   0.00000   0.00000 
> -0.41322   0.00000
>
>
> Could you suggest some possible reasons for the bad result of MD run?
>
> Thank you,
> Lu
>
>
>
> ---------------------------- Original Message ----------------------------
> Subject: Re: [gmx-users] how to simulate crystals in Gromacs
> From:    "Mark Abraham" <Mark.Abraham at anu.edu.au>
> Date:    Thu, April 7, 2011 12:05 pm
> To:      "Discussion list for GROMACS users" <gmx-users at gromacs.org>
> --------------------------------------------------------------------------
>
> On 7/04/2011 1:55 PM, ZHANG Lu wrote:
>> Dear all,
>>    I am now trying to simulate crystals in Gromacs.
>>    What I did was to convert the original crystal structure in cif format
>> to pdb format and then use genconf to replicate the cells and run MD.
>>    Is it proper to do it in this way?
> It's workable. Whether you need to replicate depends on the size of the
> periodic cell. Whether your box had enough space around the "outer"
> atoms is also a concern.
>
>>  Because the structure I got after MD
>> run was completely a mess ( not like crystals any more).
>>    Could anyone tell me the correct way to do MD simulation in crystal
>> environment?
> There are a large number of possible reasons of the problem. We simply
> do not have enough information to suggest anything.
>
> Mark




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