Re: Units

[Jean-Noël Grad]

Hi,

The way I understand it, we define an arbitrary quantity of energy [E] 
to serve as a scale, to which we assign the value of the statistical 
thermal energy of the system, [E] = 300 kbT, which has the unit of 
Joules. We instantiate the electrokinetics class with a force density of 
0.1 on the capacitor plates, so the value of the electric field E 
generated between the plates can be expressed as E = 0.1[E]/([q][x]) in 
simulation units (because V/m = J/C/m), which is equal to 0.1 * 4.14e-21 
/ 1.60e-19 / 1e-9 = 2.5875e6 J/C/m in SI units.

The notation got me confused at first, because the electric field E has 
units of Volts/meter while the energy [E] has units of Joules.

Best regards,
JN

On 12/11/19 6:46 PM, Ahmad Reza Motezakker wrote:
> Dear EspressoMD users,
>
>
> I am going through Tutorial 7: Electrokinetics​ and as you know it 
> begins with SI unit conversion to Espresso units. There is a table which 
> shows the necessary parameters for the simulation and their units. I 
> have been able to convert all the parameters but the last one which is 
> external electric fields (E).
>
> In other words, I am confused that how 2.585*10^6 (V/m) has been 
> transferred to 0.1 [E]/[q][x].
>
> I really appreciate if you could help me with this. Thank you very much.
>
>
> Best Regards,
>
> Ahmad Reza