AMBER Archive (2008)

Subject: AMBER: Problems with the charge (membrane simulation)

Date: Wed Aug 06 2008 - 13:20:30 CDT

I am trying to do a membrane+protein simulation using the Amber force
field. I have ionized with tleap, and the charge of my system was -22.95, so
Leap added 22 Na+ ions to neutralize:

 addions solvated Na+ 0
22 Na+ ions required to neutralize.

When I use this force field in NAMD, I can see that the total charge is not
zero, as is logical.

Info: TOTAL CHARGE = -0.94832 e

So, some warnings appear:

Shoud I add 23 Na+ instead of the default Leap applies? In such way, the charge
won´t be exactly zero, either. Do you think will be there problems, too?

Thank you very much for your help,

Best wishes,

Rebeca García Fandiño
Parc Cientific of Barcelona

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