this study presents an x-ray diffraction analysis and rietveld structural refinement of selected synthetic fluoroperovskite-type compounds including the na1-xkxmgf3 solid solution series in addition to synthetic analogues of cryolite (na2naalf6) and simmonsite (na2lialf6). the na1-xkxmgf3 solid solution series is comprised of three structurally distinct perovskite phases. in order of increasing potassium they are; orthorhombic (pbnm, a = 5.3609(1), b = 5.4862(1), c = 7.6661(1), z = 4) in the x = 0 - 0.35 compositional range, tetragonal (p4/mbm, a = 5.444(3), c = 3.9217(3), z = 2) in the x = 0.40 ~ 0.46 compositional range and cubic (see document)