AMBER Archive (2006)

Subject: AMBER: use_pme=0 problem

Date: Wed May 24 2006 - 18:18:47 CDT

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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