xstep and estep parameters of XANES card

[ALNemir@aol.com]

Dear FEFF8 users,

I am looking at the XANES of LiCoO2, Co edge. At some point I wanted to get a 
better resolution of a part of the plot, but it is not clear to me how to do 
that. It seems that the xstep and estep parameters of the XANES card would 
determine that. It is stated in the FEFF8 manual that "xstep specifies the size 
of the output k grid far from the edge" while "the grid at the edge will be 
regular in energy with a step size of estep." I was wondering where these 
respective regions begin and end (and if there are any additional regions in between 
them), and whether those points are fixed or floating. Though I played around 
with the above-mentioned parameters I was not able to find a definitive 
answer. Please see the enclosed pdf file for a plot of the xmu.dat files with 
different values of xstep and estep.

*On a related note, please correct me if I am wrong, but I was assuming that 
the number of points in the XANES calculation output file, xmu.dat, is related 
to the number of "energy points" specified in the log3.dat file of the FMS 
calculation.

Log3.dat:
Number of energy points = 118
 Doing FMS for a cluster of  87 atoms around iph =  0
 Please, wait (updates every 20 points) ...
        FMS matrix (LUD) at point  20, number of state kets =1224
        FMS matrix (LUD) at point  40, number of state kets =1224
        FMS matrix (LUD) at point  60, number of state kets =1224
        FMS matrix (LUD) at point  80, number of state kets =1224
        FMS matrix (LUD) at point 100, number of state kets =1224
 Done with module 3: FMS.

-The number of those "energy points" seems to have a limit of 120. Is there a 
reason for that?
-It was 118 for most of the calculations plotted in the enclosed file, except 
for the one with parameters   xmax=3, xstep=.07, estep=.01, in which was 72. 
Why is that? 
-From the log file presented above it is not clear if the last 18 points are 
calculated and written into an output file. 
-Whether the above assumption * is correct or not, I would like to know where 
the number of points in the xmu.dat file comes from. It is 100 for the 
118-energy-points cases and 54 for the 72-energy-point case.

Thank you,

Lydia Nemirovsky
Research Assistant
EXAFS Laboratory
Department of Physics and Astronomy
Hunter College