3D Models World shows how to make an Xray shader with Arnold quickly.

Way back in the day, the only way to get a center edge effect in Maya was to use dome tricks. You either had to use the ramp shader or use some utility nodes that included the standard Sampler Info. These days, thanks to physically pluasible, monolithic, and principled shaders, it’s much more manageable.

Check out this tutorial from 3D Models World that uses a bit of both the methods. “The methods used to create the Xray shader will work with any Maya/Arnold version.” This tutorial has pretty good tips and tricks for creating Xray or See through shader using any version of Maya.