[gmx-users] What is the relationship between simulation time and real time

[Mark Abraham]

Q733 wrote:
> Dear gmx-users, I have a basic question to propose: What is the 
> relationship between simulation time and the actual time a real process 
> occurs? Are they the same? Or do they have certain correlation in 
> certain situation?

That depends how good a model of reality your simulation is. The only
way to demonstrate that you have a model where simulation time might
correspond to actual time is to find some suitable experimental data,
and do a simulation that demonstrates such correspondence. Then you need
to be able to justify extrapolating from that correspondence to
correspondence for some system where you don't have experimental data.

The practical problem here is that there are not all that many sources
of accurate experimental data relating to time-scales of processes that
are of phenomena exhibited by a "small enough" physical system to permit
an accurate MD simulation to measure the same quantity for a reasonable
expenditure of computer time. I can't think of any off-hand, but maybe
others can.

Mark