  The magnetic structure of antiferromagnetic NdRhIn5 has been determined using
neutron diffraction. It has a commensurate antiferromagnetic structure with a
magnetic wave vector (1/2,0,1/2) below T_N = 11K. The staggered Nd moment at
1.6K is 2.6mu_B aligned along the c-axis. We find the magnetic structure to be
closely related to that of its cubic parent compound NdIn3 below 4.6K. The
enhanced T_N and the absence of additional transitions below T_N for NdRhIn5
are interpreted in terms of an improved matching of the
crystalline-electric-field (CEF), magnetocrystalline, and exchange interaction
anisotropies. In comparison, the role of these competing anisotropies on the
magnetic properties of the structurally related compound CeRhIn5 is discussed.
