How do I get these Radius -Surface Transisitions to be Smooth?

Tetraeder.3dm (498.1 KB)

Hey Guys! Im struggling with something here and was hoping for your help! Im building up this surface and face the following problem: How do i get a really smooth transition between the radii and the triangular flat surfaces? It looks kinda smooth but is very noticable when 3d printed. The points of the the tetrahedron have to be spherical, as thats part of the design.

Can anyone help me out? would be greatly appreciated