[gmx-users] OPLS-AA forcefield

[Justin A. Lemkul]

Erik Marklund wrote:
> Justin A. Lemkul skrev:
>>
>>
>> you zou wrote:
>>> Hi everyone,
>>>
>>> I have one simple question. I don't know is there any different 
>>> between OPLS-AA forcefield and OPLS-AA/L forcefield? I think these 
>>> are different but when I use pdb2gmx tool there is no OPLS-AA 
>>> forcefield to choose.
>>>
>>
>> There is no difference.  The presence of "/L" simply indicates it is 
>> for liquid simulations.  I am unaware of a vacuum or gas phase 
>> OPLS-AA, certainly not within Gromacs.
>>
>> -Justin
> I think that's incorrect. The 'L' in OPLS stands for 'Liquid'. The 
> trailing /L was added when some parameters were reparameteriezd 
> (dihedrals I think) at some point, but I don't know what it stands for.
> 

Oops, you're quite right!  My mistake.  I was thinking of the wrong L :)  The /L 
indicates the use of local MP2 (LMP2) for parameterization.

-Justin

> Erik
>>
>>> Thank you
>>>
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>>
> 
> 

-- 
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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

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