Recent results on the NpO2 25 K transition by neutron diffraction A. Boeuf, J.M. Fournier, G. Heger, N. Lehner, L. Manes, J. Rebizant, F. Rustichelli et J.C. Spirlet J. Physique Lett., 42 17 (1981) 401-404 DOI: 10.1051/jphyslet:019810042017040100