AMBER: use_pme=0 problem

From: <>
Date: Wed, 24 May 2006 18:18:47 -0500

Dear AMBER users,

I am trying to study a polymer system with TraPPE-united atom force field.
Since there is no partial charge in any atom of the system, I turn off PME
using "use_pme=0" and "eedmeth=4" to save the computer time. At the same
time, I perform a regular simulation (NPT) with PME on and "EW_TYPE=0". I
would expect these two simulations will give me identical or similar
results. However, I found that the potential energy of the two systems has
a big difference and the one with PME on converges much fast. Do you have
any idea about the source of this difference?


Lu Yang

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Received on Fri May 26 2006 - 21:05:19 PDT
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