Forty-six standard X-ray diffraction powder patterns are presented. Fourteen are to replace twelve patterns already given in the X-ray Powder Data File, and thirty-four are for substances not previously included. The X-ray Powder Data File is a compilation of diffraction patterns from many sources and is used for the identification of unknown crystalline materials by matching spacing and intensity measurements. The patterns were made with a Geiger counter X-ray diffractometer, using samples of high purity. The d-values were assigned Miller indices determined by comparison with calculated interplanar spacings and from space group considerations. The densities and lattice constants were calculated, and the refractive indices were measured whenever possible.

Aluminum Metaphosphate, Al (P03)3(cubic) 3 *Antimony(III) Fluoride, SbFs (orthorhombic) . 4 *Barium Arsenate, Ba3(As04)2) (trigonal) 6 Barium Perchlorate Trihydrate, Ba(C104)2-3H20 (hexagonal) 7 *Cadmium Cyanide, Cd(CN)2 (cubic) 8 Cadmium Tungstate, CdW04 fmonoclinic) 8 *Cesium Bromoosmate(IV), Cs20sBr6 (cubic) 10 *Cesium Cliloroosmate(IV), Cs20sCl6 (cubic) 11 Chromium Orthophosphate, alpha, CrP04 (orthorhombic) 12 *Cobalt Mercury Thiocyanate, Co[Hg(CNS)4] (tetragonal) 13 Cobalt Sulfate, beta, C0SO4 (orthorhombic) 14 *Dysprosium Gallium Oxide 3:5, DyGa2(Ga04)3 (cubic) 15 *Erbium Manganite, ErMn03 (hexagonal) 16 *Europium Gallium Oxide 3:5, Eu3Ga2(Ga04)3 (cubic) 17 *Gadolinium Gallium Oxide 3:5, Gd3Ga2(Ga04)3 (cubic) 18 *Lithium Arsenate, Li3As04 (orthorhombic) 19 *Lithium Trimetaphosphate Trihydrate, LisPsOg-SHaO (trigonal) 20 •Not previously listed in the Powder Data File. Page *Lithium Tungstate Hemihydrate, Li2W04-y2H20 (cubic) *Lutetium Gallium Oxide 3:5, Lu3Ga2(Ga04)3 (cubic) *Lutetium Manganite, LuMnOs (hexagonal) Manganese (II) Tungstate (huebnerite) , MnW04 (monoclinic) *Mercury(II) Fluoride, HgF2 (cubic) Nickel Sulfate, NiS04 (orthorhombic) *Nickel Tungstate, NiW04 (monoclinic) Potassium Chlororhenate, K2ReCl6 (cubic) Potassium Nitroso Chlororuthenate, K2RUCI6NO 29 *Rubidium Perchlorate, RbC104 (orthorhombic) _ *Rubidium Periodate, RbI04 (tetragonal) 31 *Silver Selenate, Ag2Se04 (orthorhombic) *Sodium Cyanate, NaCNO (trigonal) Sodium Orthotungstate(VI) Dihydrate, Na2W04-2H20 (orthorhombic) 33 Sodium Tetrametaphosphate Tetrahydrate, high form Na4P40i2-4H20 (triclinic) Strontium Arsenate, Sr3(As04)2 (trigonal) *Thallium(I) Arsenate, TI3ASO4 (hexagonal) Thallium (I) Perchlorate, TICIO4 (orthorhombic) Yttrium Arsenate, YAsO^(tetragonal) 39 Zinc Tungstate, ZnW04 (monoclinic)