Mixed material setup issues

[Z-zhq]

Hi, how do I set up a mixed material, such as borosilicate glass

[kklmn]

Hi,
Give a list of the elements, a list of their quantities and the material density (rho), see here.

[Z-zhq]

Hi, how do I set the roughness of a surface of a mixed material?

[kklmn]

Materials in xrt are used to quantify the interaction of atoms with x-rays. Roughness and other geometry-related aspects belong to optical elements.

[Z-zhq]

Could you please elaborate on how to adjust the roughness of optical elements? Why do I only see the roundness variable in the Coated?