espressomd-users
[Top][All Lists]

## [ESPResSo-users] Mass scale in simulations

 From: geiselda Subject: [ESPResSo-users] Mass scale in simulations Date: Wed, 22 May 2019 11:08:40 +0200 User-agent: Horde Application Framework 5

Dear all,

I have a question concerning the mass scale of the simulations in espresso.
The documentation states that

"By default, ESPResSo uses a reduced mass of 1,
so that the mass unit is simply the mass of all particles."
(http://espressomd.org/html/doc/introduction.html#on-units)


How is this statement to be interpreted? Does the time scale of my simulations change
when I add particles to the simulation, like

[time] = [length] \sqrt{ #particles* [mass] / [energy] }


or do I still only use the mass of one particle and assume that all particles have the same mass?


To test this I constructed a simple simulation of diffusing particles and calculated the diffusion coefficient of a single particle (which should be independent of the number of
particles in the box (no interactions)).

Here, it seemed as if the time scale was independent of the number of particles. Is this correct?

I would be very thankful for advise,

best regards,
David.