Re: AMBER: Employing SCC-DFTB with a periodic boundary condtion

From: Gustavo Seabra <>
Date: Thu, 26 Apr 2007 09:18:32 -0400

> Dear all users.
> I was going to use SCC-DFTB for QM/MM simulation, but I wonder if I can use the method with a periodic boundary condition. The manual says SCC-DFTB implementation does not support Ewald summation, so I used qm_ewald=0 in the &amp;qmmm namelist. However, if I use NTB=1 in the &amp;cntrl namelist for a periodic boundary condition, PME is always on. Then, can my simulation work properly without any problems?
> Thanks
> Jaebeom.
Yes, it should work. Although PME over the *classical* atoms is on,
qm_pme will be off. You will not have Ewald or PME tratment for long
range electrostatics involving the QM atoms, so you may have to use a
large cutoff, but otherwise you should have no problems.

BTW, this issue has been solved for the next release (Amber 10).

The AMBER Mail Reflector
To post, send mail to
To unsubscribe, send "unsubscribe amber" to
Received on Sun Apr 29 2007 - 06:07:22 PDT
Custom Search