(no subject)

Dear Sir,

please always send a copy of your replies to the mailing list.

What should be the appropriate size of the system say,
pure water for which I should get correct behavior at the
end of the simulation.

the behavior *is* correct. there will *always* be fluctuations.
what matters are the averages. i suggest you look up the
details on the subject by searching for equipartition theorem
in your stat mech text book.