Re: AMBER: TI calculation: charge is not zero in the perturbed state

From: David A. Case <>
Date: Sat, 3 Mar 2007 13:11:52 -0800

On Sun, Mar 04, 2007, wrote:

> Also I checked the charge of the system before loading the .frcmod file and
> found to be zero, but unfortunately after loading .frcmod the charge of the
> system is not zero (-0.158200),

First, please try to send email as plain text, not html...thanks

Your report is weird, since loading a frcmod file should have no effect on the
charges. What were the exact commands you used to check the charges before
and after the frcmod loading?

Note that -0.1582 is exactly twice -0.0791, which may point you to something.
In the table you sent, you had a dummy atom (CD1 in the perturbed state) with
a non-zero charge ( -0.0791). Since dummy atoms should never have a charge,
I am sure this is not what you want. But it is not easy to see how this
happened from you description.

...good luck...dac

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Received on Sun Mar 04 2007 - 06:08:10 PST
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