[gmx-users] re K+ ion

Yang Ye leafyoung81-group at yahoo.com
Thu Jan 19 13:21:52 CET 2006


have a try with a system just with two atoms, Na+ and Cl-.

taveechai taveecharoenkool wrote:
> Dear Yang,
>  Thanks again.
> i got this line
> atom[ 52281]={type= 25, typeB= 25, ptype=    Atom, m=
> 3.90983e+01, q= 1.00000e+00, mB= 3.90983e+01, qB=
> 1.00000e+00, resnr=13633} grpnrs=[ 3 3 0 0 0 0 0 0 0
> ]}
> which should mean my K+ has +1 charge. and there is no
> NB interaction from
> excl[52281][211661..211661]={52281}. Now , i just
> wonder when i use g_saltbr it doesn't say interaction
> of K+ and CL- ions. My system contains 488 K+ and 488
> CL-.
>
> --- Yang Ye <leafyoung81-group at yahoo.com> wrote:
>
>   
>> taveechai taveecharoenkool wrote:
>>     
>>> Hi Yang,
>>>  I don't understand what you mean, please give me
>>>       
>> an
>>     
>>> example.
>>> i see 
>>>  excl:
>>>             multinr[division over processors]:
>>>       
>> 52414 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
>>>       
>> 0 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
>>>       
>> 0 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
>>>       
>> 0 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
>>>       
>> 0 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
>>>       
>> 0 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
>>>       
>> 0 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
>>>       
>> 0 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
>>>       
>> 0 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
>>>       
>> 0 0
>>     
>>> 0 0 0 0 0 0 0 0 0 0 0
>>>             nr=52414
>>>             nra=211794
>>>             excl[0][0..5]={0, 1, 2, 3, 4, 5}
>>>             excl[1][6..13]={0, 1, 2, 3, 4, 5, 6,
>>>       
>> 18}
>>     
>>>             excl[2][14..19]={0, 1, 2, 3, 4, 5}
>>>             excl[3][20..30]={0, 1, 2, 3, 4, 5, 6,
>>>       
>> 7,
>>     
>>> 18, 19, 20}
>>>             excl[4][31..38]={0, 1, 2, 3, 4, 5, 6,
>>>       
>> 18}
>>     
>>> what does this mean?
>>> Please help,
>>>   
>>>       
>> excl[0][0...5] means for atom #0 (find this in your
>> gro file) has 6 
>> exclusion respectively to atom #0, #1, #2,...,#5.
>> In your problem, you may locate the atom # for K and
>> find its' exclusion 
>> list. Exclusion means there is no NB interaction
>> between the pair.
>> You can also check the charge for K in the dump
>> file.
>>     
>>> --- Yang Ye <leafyoung81-group at yahoo.com> wrote:
>>>
>>>   
>>>       
>>>> use gmxdump -s to check whether there is
>>>>         
>> exclusion
>>     
>>>> between them (look 
>>>> for "excl")
>>>>
>>>> taveechai taveecharoenkool wrote:
>>>>     
>>>>         
>>>>> Dear Jochen,
>>>>> thanks very much for your reply. Anyway, i
>>>>>           
>> already
>>     
>>>>>       
>>>>>           
>>>> did
>>>>     
>>>>         
>>>>> what you suggest. I can run without the problem.
>>>>>           
>> I
>>     
>>>>> want to analyze the system after 1ns or 2ns,
>>>>>           
>> when
>>     
>>>>>       
>>>>>           
>>>> i
>>>>     
>>>>         
>>>>> use g_saltbr which tell the oppositely
>>>>>           
>> two-charged
>>     
>>>>> groups. it doesn't have interaction of K+ and
>>>>>       
>>>>>           
>>>> negative
>>>>     
>>>>         
>>>>> charge. I quite don't understand.. where my K+
>>>>>       
>>>>>           
>>>> charge.
>>>>     
>>>>         
>>>>> --- Jochen Hub <jhub at gwdg.de> wrote:
>>>>>
>>>>>   
>>>>>       
>>>>>           
>>>>>> taveechai taveecharoenkool wrote:
>>>>>>
>>>>>>     
>>>>>>         
>>>>>>             
>>>>>>> Dear all,
>>>>>>> I want to study the effect of K ion on a
>>>>>>>           
>>>>>>>               
>>>> protein.
>>>>     
>>>>         
>>>>>>>       
>>>>>>>           
>>>>>>>               
>>>>>> I
>>>>>>     
>>>>>>         
>>>>>>             
>>>>>>> add this line in ions.itp 
>>>>>>> [ moleculetype ]
>>>>>>> ; molname	nrexcl
>>>>>>> K+		1
>>>>>>> [ atoms ]
>>>>>>> ; id	at type res nr	residu name	at name  cg nr
>>>>>>>               
>>>>>>>       
>>>>>>>           
>>>>>>>               
>>>>>> charge
>>>>>>     
>>>>>>         
>>>>>>             
>>>>>>>  mass
>>>>>>> 1	K+	1	K+		K	1	1	 39.0983  
>>>>>>> it seems ok, i can run (mdrun) without error.
>>>>>>>           
>>>>>>>               
>>>> The
>>>>     
>>>>         
>>>>>>> thing in my mind is that is it enough (to edit
>>>>>>>           
>>>>>>>               
>>>> only
>>>>     
>>>>         
>>>>>>> one file) cos it seems like K+ doesn't contain
>>>>>>> positive charge when i used g_saltbr? i use
>>>>>>>       
>>>>>>>           
>>>>>>>               
>>>>>> Gromos96
>>>>>>     
>>>>>>         
>>>>>>             
>>>>>>> forcefield.
>>>>>>> Thanks in advance
>>>>>>>
>>>>>>>       
>>>>>>>           
>>>>>>>               
>>>>>> You should add a
>>>>>> K+      1
>>>>>>
>>>>>> into the [ molecules ] section of your
>>>>>>             
>> topol.top.
>>     
>>>>>> And , of course, you need to place it into your
>>>>>> starting structure (pdb 
>>>>>> or gro).
>>>>>>
>>>>>> Jochen
>>>>>>
>>>>>> -- 
>>>>>>
>>>>>>             
>> ************************************************
>>     
>>>>>> Jochen Hub
>>>>>> Max Planck Institute for Biophysical Chemistry
>>>>>> Computational biomolecular dynamics group
>>>>>> Am Fassberg 11
>>>>>> D-37077 Goettingen, Germany
>>>>>> Email: jhub[at]gwdg.de
>>>>>>
>>>>>>             
>> ************************************************
>>     
>>>>>>
>>>>>>     
>>>>>>         
>>>>>>             
>> __________________________________________________
>>     
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>>>>>   
>>>>>       
>>>>>           
>>>> -- 
>>>> /Regards,/
>>>> Yang Ye
>>>> /Computational Biology Lab
>>>> School of Biological Sciences
>>>> Nanyang Technological University
>>>> Singapore
>>>> Tel: 6316-2884
>>>> /
>>>>
>>>>     
>>>>         
>>> __________________________________________________
>>>       
> === message truncated ===
>
>
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-- 
/Regards,/
Yang Ye
/Computational Biology Lab
School of Biological Sciences
Nanyang Technological University
Singapore
Tel: 6316-2884
/



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