[gmx-users] Re: thermal conductivity,specific heat,enthalpy

[Ahmet yıldırım]

could anybody help me please?


2013/4/11 Ahmet yıldırım <ahmedo047 at gmail.com>

> Dear users,
>
> I calculated diffusion constant of a substance using g_msd tool.  I also
> want to calculate thermal conductivity its. By the way,I did npt simulation.
>
> Diffusion constant=alpha
> Thermal conductivity=k
> specific heat=Cp
> density=d
> alpha=k/(d.Cp)
> and
> k=alpha.d.Cp
> I need d and Cp to calculate k.
>
> 1.) To calculate Cp:
> Prof. Spoel:From
> http://www.mail-archive.com/gmx-users@gromacs.org/msg37580.html
>
> cP = (<H^2> - <H>^2)/kB T^2 (NPT sim)
>
> The .edr file gives average enthalpy <H>. According to above formula, I
> need both H and <H>. How can I get H (not average)?
> 2.) .edr file:
>   1  LJ-(SR)          2  LJ-(LR)          3  Coulomb-(SR)     4
> Coul.-recip.
>   5  Potential        6  Kinetic-En.      7  Total-Energy     8
> Temperature
>   9  Pressure        10  Box-X           11  Box-Y           12
> Box-Z
>  13  Volume          14  Density         15  pV              16
> Enthalpy
>  17  Vir-XX          18  Vir-XY          19  Vir-XZ          20
> Vir-YX
>  21  Vir-YY          22  Vir-YZ          23  Vir-ZX          24
> Vir-ZY
>  25  Vir-ZZ          26  Pres-XX         27  Pres-XY         28
> Pres-XZ
>  29  Pres-YX         30  Pres-YY         31  Pres-YZ         32
> Pres-ZX
>  33  Pres-ZY         34  Pres-ZZ         35  #Surf*SurfTen   36
> Mu-X
>  37  Mu-Y            38  Mu-Z            39  T-System        40
> Lamb-System
> Firstly I calculated Entalphy (16)
> Afterward I calculated both Etot (7) and pV (15)
> Enthalpy=Etot+pV
> Unfortunately, I get "Enthalpy isnt equals to Etot+pV". Why?
>
>
> --
> Ahmet Yıldırım
>



-- 
Ahmet Yıldırım