Re: AMBER: temperature keep increasing in high temp.

From: Carlos Simmerling <>
Date: Fri, 29 Jul 2005 20:28:42 -0400

Hwankyu Lee wrote:

>Dear Amber-users,
>I'm trying simulations with high temperature (363K), but after 82ps, the
>temperature suddenly increased, showing errors like below, and then system
>First, I ran the system from 0K to 363K with restraints for 20ps
heating this fast can cause real problems, especially starting from
0K. keep in mind that you are increasing velocities by a huge factor
over this range. try assigning velocities at a higher T, or heat
more slowly. Langevin dynamics can also help. If you have even
the slightest hot spot at the low T (say at 1K part of the system
is at 2K), then when you rapidly scale to 360K the spot that was
only 1K hotter is now 720K! 20ps isn't slow enough to redistribute
that energy.


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Received on Sat Jul 30 2005 - 01:53:01 PDT
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