Getting HOLZ lines to show up in an ECP

[j-raub]

Hello,

As the title suggests this is about generating ECP. I'm trying to get a high quality close up of a zone axis with HOLZ lines similar to what can be seen in https://doi.org/10.1017/S1431927614001937 . I was tinkering with the parameters for EMECPSingle as well as the BetheParameters but my best results are still quite blurry and far from the quality seen in that paper.

Here's an example of my results for the Silicon (1 0 0) axis with an opening angle of +-2.4°:

The Namelist file:

&ECPSinglelist
! The line above must not be changed
!
! The values below are the default values for this program
!
! smallest d-spacing to take into account [nm]
 dmin = 0.025,
! monte carlo energy file
energyfile = 'mc-Si_20kV_80deg_2.h5'
! size of output pattern in pixels (image is always square npix x npix)
 npix = 256,
! half angle of cone for incident beams (degrees)
 thetac = 2.4,
! mask pattern or not; 'y' or 'n'
 maskpattern = 'y',
! euler angles (in degrees)
phi1 = 45.D0
phi = 0.D0
phi2 = 0.D0
! euler angle convention in input angle file; 'hkl' or 'tsl'
 eulerconvention = 'hkl',
! gamma scaling value
 gammavalue = 1,
! output file ; path relative to EMdatapathname
 datafile = 'single_2.4deg_4.h5',
! number of threads for parallel execution
 nthreads = 20,
! tilt of the sample; only one angle incorporated for now
 sampletilt = 0.D0,
! detector geometry parameters
! working distance [in mm]
 workingdistance = 5.0,
! inner radius of annular detector [in mm]
 Rin = 2.0,
! outer radius of annular detector [in mm]
 Rout = 6.0,
!
 /

The BetheParameters:

 &Bethelist
! Do not change the line above !
!
! Details about the particular implementation of the Bethe potentials can be 
! found in the recent paper: A. Wang & M. De Graef, "Modeling dynamical electron
! scattering with Bethe potentials and the scattering matrix" Ultramicroscopy,
! vol 160, pp. 35-43 (2016)
!
! strong beam cutoff
 c1 = 40.0,
! weak beam cutoff
 c2 = 60.0,
! complete cutoff
 c3 = 500,
! double diffraction reflections: maximum excitation error to include [nm^{-1}]
 sgdbdiff = 1.00
 /

Acceleration voltage was fixed at 20 keV.

I kept npix intentionally low to cut down on computation time during testing, which is already taking quite long on my setup with these parameters. From my understand the critical parameters for this should be dmin and the Bethe parameters c1, c2 and c3. I think dmin = 0.025 nm should be small enough since the (2 16 2) HOLZ line should have a spacing of roughly 0.033 nm.

Going down with the Bethe params to c1=10, c2=20, c3=50 gives me a less blurry ECP but also just not right:

If somebody has experience with this sort of thing I would really appreciate the help. :)

(Also: Is the gammavalue parameter broken? It does not seem to change the result for me.)

Cheers,
j-raub