Citation: Laguna, M A; Sanjuan, M L; Orera, V M; Rubin, J; Palacios, E; Pique, M C; Bartolome, J; Berar, J F (1993). X-ray and raman study of the low temperature NH~4~MnF~3~ structure;evidence of librational motion of the NH~4~^+^ ion. Journal of Physics: Condensed Matter, 5, pp. 283-300.