Rietveld analysis of neutron‐diffraction data from Nd3Fe29−xTx(T=Ti, Cr, and Mn) has been used to determine the location of the substitutional atoms and the magnetic moments. Reanalysis of the T=Ti data confirms that the space groupA2/mis a better choice thanP21/c, which had previously been used to describe the structure. The Ti atom locations and concentrations remain unaffected in the two space groups, but for the other substituents the refined concentrations are well behaved inA2/m, whereas inP21/cthe refinements were unstable due to the symmetry relations between certain substituted sites. The site occupancies are analyzed in terms of steric and environment effects. A possible explanation for the high Curie temperature of the Cr compound is proposed. ©1996 American Institute of Physics.