fix qeq/comb

Hey folks,

I have a question about fix qeq/comb. On the doc page, it mentions both the Rappe and Goddard paper and the Rick, Stuart, and Berne paper for the charge equilibration. However, as I understand it, the Rappe and Goddard paper presents a Matrix inversion method for solving the charges, while the Rick, et al. paper uses the extended Lagrangian method. From the doc page, it is unclear which of these methods is employed in qeq/comb. A version currently available from Susan Sinnott’s group on their software site uses damped charge dynamics to minimize the charges, though I’m not sure I would call it an extended Lagrangian method.

On a similar note, I was wondering if Ray worked on the version that the Sinnott group recommends and has the source code on their site as I mentioned above. I have questions about it, but since it’s not packaged with LAMMPS I didn’t imagine you all would be very familiar with it.

Thanks for your help.

Seth Martin

CCing Ray …