Hi all. I'm trying to figure out what the Ewald screening parameter is (I've also heard it called the convergence, or splitting parameter) given the chosen precision. From looking through the code I think the g_ewald (G vector) is what I'm looking for - the thing that controls the width of the screening gaussian. I think the units are right - one over length. Is the value of the G vector printed in the output consistent with the units chosen in the input?

Thanks,

Matt

Yes, that is what g_ewald is. I recall there is a factor

of sqrt(2) difference in the definition of g_ewald between

Ewald and PPPM, so it's not an absolute value, just a numeric one.

Don't know what you mean by units chosen in the input.

The input precision and cutoff are transformed into a g_ewald

value.

Steve

Thanks Steve. The question I have about units is, if I define my units as real in my input, is the value of the G vector printed to the log file in inverse Angstroms? From what I can sort out the units of G vector is consistent with units chosen in the input file.

Matt

Quoting Steve Plimpton <[email protected]>:

yes, I think that's correct.

Steve