AMBER Archive (2006)

Subject: Re: AMBER: Temperature fluctuation with Langevin Temperature control

From: Adrian Roitberg (
Date: Sun Aug 27 2006 - 16:07:07 CDT

Gobind Singh Bisht wrote:
> Dear amber users,
> I'm trying to run my simulations at a constant
> temprature using the Lamgevin temperature control. But there are large
> temprature fluctuations (rms 4K). Since I am simulating a small piece of
> (42 bp) with implicit solvation I'm equillibrating for only 20ps (with
> delta
> T= 4K). Could that be the reason for the temp fluctuation? Why is there a
> temp fluctuation at all when i specify a target temp. Can someone explain
> me. sry but i'm new to MD and AMBER.
> thanx in advance
Why do you think 4K is too much of a fluctuation ?

I think you need to understand the langevin thermostat a bit better
before you can say that 4 K is too much, too little or just right.


                            Dr. Adrian E. Roitberg
                              Associate Professor
               Quantum Theory Project and Department of Chemistry

University of Florida PHONE 352 392-6972 P.O. Box 118435 FAX 352 392-8722 Gainesville, FL 32611-8435 Email ============================================================================

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