Dear list,

I made an EXAFS analysis in Artemis (in Demeter 0.9.22) using all the available variables. This is a fragment of the .log file I got:

Independent points : 17.7666016

Number of variables : 17

Chi-square : 265.0947132

Reduced chi-square : 345.8050781

R-factor : 0.0026486

Number of data sets : 1

: k-range = 2.942 - 11.043

: dk = 1

: k-window = hanning

: k-weight = 1,2,3

: R-range = 1.115 - 3.5

: dR = 0.0

: R-window = hanning

: fitting space = r

: background function = yes

: phase correction = no

: background removal = E0: 20002.215, Rbkg: 1.0, range: [2.25:17.4039986832903], clamps: 0/24, kw: 2

: epsilon_k by k-weight = 3.189e-004

: epsilon_r by k-weight = 2.339e-001

: R-factor by k-weight = 1 -> 0.00220, 2 -> 0.00224, 3 -> 0.00392

The problem is that when I use the Nyquist criterion

Nind=2*deltak*deltar/pi + 1

for calculating the number of independent points the value I got is much lower and close to 13.

I was not aware of this discrepancy and it caused a reviewer to think I made up the fit!

Am I doing something wrong?

Is there another way to calculate the Nind that might have been used by Artemis?

I would really appreciate any help.

Yours

Jesús