Archerite

H_0.88K_0.78N_0.22O₄P

Ono, Y.Yamada, N.Hikita, T.

Journal of the Physical Society of Japan (1991) 60, 2673-2677

a=7.4398Å   b=7.4398Å   c=7.0454Å

α=90°   β=90°   γ=90°