[gmx-users] Re: About lipid simulation...

[rama david]

> Hi Gromacs friends
>>
>>
>>
>> I read the Gromacs manual for 4.5.4, Section 3.4 page no 33,
>> Surface tension coupling work with only Berendsen Press coupling.
>>
>> Please , would you tell me how to calculate lateral surface tension from
>> P|| ( lateral press ) and  Pz( Perpendicular press )  ???
>> ( Why to say  P||  =   -30  Pz = 1 , will give the teral tension of
>> 20 mNm/m  ???)
>>
>>
>
>
> I found out the way to calculate the lateral pressure..
>
>  As per the article ..Biophysics Journal, October 1995, vol 65, page no
>  1230.
>
>  The formula as per article is
>
>  Boundary lateral press =  1 -   ( Surface Tension / Thickness in Z
> dimension.)...
>
>
> ; Temperature coupling is on
> tcoupl        = Berendsen            ; More accurate thermostat
> tc-grps        = Protein DPPC    SOL_CL    ; three coupling groups -
> more accurate
> tau_t        = 0.1    0.1    0.1            ; time constant, in ps
> ref_t        = 323     323    323            ; reference temperature,
> one for each group, in K
> ; Pressure coupling is on
> pcoupl        =  Berendsen        ; Pressure coupling on in NPT
> vectors, independent z
> tau_p        = 0.5                    ; time constant, in ps
> ref_p        =  -30.0    1.0                ; reference pressure, x-y,z (in
> bar)
>
> compressibility = 5.0e-5    5.0e-5    ; isothermal compressibility, bar^-1
> pcoupltype    = ????????
>
> What pcoupltype  shouild be used ???
> semiisotropic or Surface-tension ????
>
>
>>
>> Please give me the valuable suggestion in these regard....
>>
>> Thank you in advance.
>>
>> Have a nice Day.
>> With best wishes and regards,
>>
>>
>> Rama David
>
>