For the Point, and Sphere particles shapes, you get a single Arnold points node. For example, for the Sphere shape, you’d get a points node that looked something like this:

points
{
 name pointcloud.SItoA.Sphere.5000
 points 54 1 b85POINT
8LLwt8;`)381]^28S`W`8:l)EadWuf8[iB>89m7taW>aAaX=rn8...
 radius 54 1 b85FLOAT
!8Fcb9$$$$Z
 mode "sphere"
 visibility 255
 sidedness 255
 matrix
 1 0 0 0
 0 1 0 0
 0 0 1 0
 0 0 0 1
 shader "Sources.Materials.DefaultLib.Material.standard.SItoA.5000.2.sta_shading_group"
 id 832
}

This particular node is for 54 points in sphere mode. For each point, you get the center position (the points.points parameter) and a radius (the points.radius parameter). If there’s any scaling applied to the particle in ICE, the radius is multiplied by the X scaling of the particle.

For the Point shape, you get an Arnold points node in “disk” mode, with radius = size * X scaling.

For the other supported shapes, you get the corresponding Arnold shape.