Subject: Experience with the combined QM/MM forcefield

From: [email-masked] (Howard Alper)
Date: Thu, 16 Jan 1997 17:44:40 -0800

Hi,

	I am looking for information on the behavior of the combined
Quantum/Classical forcefield (QM/MM), especially as implemented in
CHARMM.

1)	What types of systems, processes, or conditions, would necessitate
the use of an ab-initio QM/MM forcefield?  For what situations would a
semi-empirical version suffice?

2)	What are the changes in computational speed attendant to using
the ab-initio vs. the semi-empirical versions of the QM/MM forcefield?

	Thanks in advance.  I will summarize to the list after all the
responses are in.

	Howard

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