2014 Using an X-ray diamond anvil cell, we have found superlattice reflections, characteristic of the high pressure-low temperature phase III of NH4HC2O4, 1/2 H2O. At 77 K and 0.75 GPa, these peaks are located around each Bragg peaks of phase I at position (h, k, 1 ± 03B4) with 03B4 ~ 0.25. Revue Phys. Appl. 23 (1988) 105-109 FÉVRIER 1988, Classification Physics Abstracts 61.10F 61.50K 62.50 64...
