Shell diameter vs shell width

[Mensel123]

Hi,

First, thanks so much for this great package. Very impressive work!

While trying to get myself more acquainted with the package I got a bit confused about the use of shell_width vs shell_diameter in a CoreShell particle.

shell_width is used in a CoreShell particle (see) and shell_diameter is used in a CoreShellSet (see). I assume both refer to the thickness of the shell? However, when I look at one of your examples you set the shell_diameter to 800 nm and the core_diameter to 400 - 600 nm, suggesting shell_diameter does not refer to the thickness of the shell but to the diameter of the entire particle.

So could you clarify for me if shell_width and shell_diameter refer to the same thing and if so, if they mean the thickness of the shell?

[MartinPdeS]

Hi! Thanks for reaching out. I know that the variables name are a bit misleading but for the lack of better idea I kept them this way. Here are the definitions of the variables:

• core_diameter: the diameter of the spherical center part of the scatterer.
• shell_width: is the additional width added to the core.

Thus for instance a CoreShell scatterer having shell_width set to zero would be equivalent to a simple Sphere scatterer.

Moreover a CoreShell having:

• core_diameter of 600 nm
• shell_width of 100 nm

Would have a total diameter of 800 nm (600 + 2 * 100)

In the very next version I will add this information into the documentation. If this API causes too much trouble I will consider changing it.

Thanks for pointing out this problem!

[Mensel123]

Thanks for your reply! That makes it already a lot clearer.

And for the shell_diameter and shell_width, are these the same values?

[MartinPdeS]

Sorry for the delayed answer. Accordingly to my last comment, the shell_diameter parameter was removed and replaced with shell_width in the new version: 0.10.13. I have a few problems with binary distribution for the macOS_x64 currently, but I reckon it will be fixed by the end of the week. Don't hesitate to contact again if needed.

[Mensel123]

Perfect! Thanks a lot.