Hi experts, 

I am new to MS. I am practicing on simulating methane diffusion on Butadiene polymer as shown in the tutorial. I got to the point where I need to convert .xtd file to .xsd file by a simple copy and paste but so far it doesn't work. Once I copy the .xtd file, I can't paste into the new 3D atomistic doc.Why is that? Kindly assist.