Subject: Re: CCL:MD or MC

From: Rafael Iosef Najmanovich Szeinfeld {S <[email-masked]>
Date: Thu, 10 Nov 1994 10:06:43 -0200 (EDT)

There's a serious difference between Monte Carlo (MC) and Molecular 
Dynamics (MD), in fact I consider them as two complementar methods.
	In a MC simulation you must neglect the first configurations
usually 10 Monte Carlo Steps (one MCS may be defined as N configurations
where N is number of degrees of freedom, you can think about it as a unit
of time) so to ensure that your data comes from equilibrium configurations
(independent of the initial condition).
	In a MD simulation you have to solve numerically the equations of
movement for each atom using a time-consuming hamiltonian (because the
potencial term accounts for all the other atoms), so the total simulation 
time may be to short to arrive equilibrium.
	Concluding, if you want to study equilibrium properties then you
must choose MC while if you want to study non equilibrium properties 
(strongly dependent on your initial conditions) then you must choose MD.
	Sincerly yours,
				Rafael.

*---------------------------------------------------------------------------*
*Rafael Iosef Najmanovich Szeinfeld   |SMAIL: Depto. de Bioquimica - B10 INF*
*Dept. Biochemistry  -Chemistry Inst. |       Universidade de Sao Paulo     *
*Dept. Math. Physics -Physics Inst.   |       Av. Prof. Lineu Prestes 748   *
*University of Sao Paulo              |       CEP 05508-900                 *
*E-MAIL : [email-masked]   |       Sao Paulo - SP - Brazil       *
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