Comparison of schemes • terms

Objective

This example checks for consistency of the four calculation schemes for the calculation of far-field cross-sections. The structure consists of four gold spheres in water arranged in a helix.

This simulation uses the following template

ModeAndScheme 2 {scheme}
MultipoleCutoff 8
Wavelength 300 900 300
Medium 1.7689 # epsilon of water
Incidence  0.0 0.0 0.0 # default along z
OutputFormat HDF5 xsec_{scheme}
Scatterers 4
Au 100.0000  0.00000 -30 20.0
Au  80.9017 58.77853 -10 20.0
Au  30.9017 95.10565  10 20.0
Au -30.9017 95.10565  30 20.0

where {scheme} is replaced by 0,1,2,3 in each separate run. The results are stored in separate output folders and collated for comparison. Note that Scheme=0 does not calculate orientation-averaged quantities.

Orientation-averaged results

We first check that orientation-averaged cross-sections are consistent for Schemes 1 to 3,

Rows: 24,381
Columns: 6
$ scheme     <chr> "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1",…
$ wavelength <dbl> 300, 300, 300, 300, 300, 300, 300, 300, 300, 302, 302, 302,…
$ crosstype  <chr> "Abs", "Abs", "Abs", "Abs", "Abs", "Abs", "Abs", "Abs", "Ab…
$ variable   <chr> "total", "I1", "I2", "I3", "I4", "I5", "I6", "I7", "I8", "t…
$ dichroism  <dbl> 1.823040e-01, 3.157315e-01, -2.057442e-01, 3.855385e-02, 3.…
$ average    <dbl> 8.400046e+03, 2.048282e+03, 3.534238e+03, 2.132195e+03, 5.8…

Fixed-orientation results

Similarly, we check the linear polarisation cross-sections at fixed orientation,

Rows: 32,508
Columns: 8
$ scheme        <chr> "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "…
$ wavelength    <dbl> 300, 300, 300, 300, 300, 300, 300, 300, 300, 302, 302, 3…
$ crosstype     <chr> "Abs", "Abs", "Abs", "Abs", "Abs", "Abs", "Abs", "Abs", …
$ variable      <chr> "total", "I1", "I2", "I3", "I4", "I5", "I6", "I7", "I8",…
$ polarisation1 <dbl> 8064.382572, 887.907883, 3655.980635, 1796.189835, 1302.…
$ polarisation2 <dbl> 7979.054678, 1893.579424, 1601.175597, 3198.189754, 713.…
$ dichroism     <dbl> 85.327894, -1005.671541, 2054.805038, -1401.999920, 588.…
$ average       <dbl> 8021.718625, 1390.743653, 2628.578116, 2497.189795, 1007…

Last run: 05 December, 2023