%0 Journal Article %A O. V. Yakubovich %A O. K. Melnikov %A V. S. Urusov %T The framework of mixed nature in $\mathrm{Na}_3\{\mathrm{Fe}_2\mathrm{Fe}_3[\mathrm{PO}_4]_2\}$ crystal structure – a new homeotype in the series of natisite %J Doklady Akademii Nauk %D 1995 %P 615-620 %V 342 %N 5 %U http://geodesic.mathdoc.fr/item/DAN_1995_342_5_a10/ %G ru %F DAN_1995_342_5_a10