Hard disk radial distribution function

[Jeno]

Hi, i am running a hard disks molecular dynamics simulation. I would like to compare the radial distribution function obtained from my simulation with the theoretical radial distribution function. May i know what is the theoretical radial distribution function? Or what data do people normally compare with when they do molecular dynamic simulation?

Thank you.

 

[Timo]

In statistical physics, there is not "the theory", but a variety of theory approaches. From my experience, theory for hard-core interactions is unreliable. I'm working on a model with hard-core interaction for which a whole zoo of theory approaches and results exist - and most of them are wrong. I don't know how accurate correlation functions from theory predictions are. But I would not compare radial distribution functions to theory results unless I have reason to believe this particular result to be correct (of course you can be pragmatic, compare, and call the theory result correct if it fits your data ). One option is to compare to experiment. Assuming you want to test your code: just compare to a different computer simulation (worst case I could dig out my old Monte Carlo code, but you probably want to compare against published data, anyways). Also note that searching Google Scholar for "hard disk fluid radial distribution function" gives about 24000 hits; it's not exactly an exotic model or observable that you are looking at.