p-Phenylenediamine dihydrochloride의 結晶構造를 X-線 廻折法을 利用하여 解明하였다. 이結晶은 三斜晶係에 屬하며, 空間群은 $C_i1-P{ar1}$ 이고, 格子常數는 $a= 4.38{pm}0.02, b=5.90{pm}0.02, c=8.76{pm}0.03{AA}, {alpha}=1101{pm}1, {eta}=96{pm}1^{circ}$이다. 그리고 單位格子속에는 들어있는 化學單位數,Z는 1이다. 各原子의 座標는 a, b 및 c軸에 따른 二次原的인 電子密度의 投影 및 ($F_o-F_c$) 合成에 依하여 얻었다. 이 結晶構造와 이미 硏究된 aliphatic diamine의 hydrogen halide 들의 構造와를 比較하였다.
The crystal structure of p-phenylenediamine dihydrochloride has been determined from X-ray oscillation and Weissenberg photographs. The crystal is triclinic, space group $C_i1-P{ar1},$ with cell dimensions $a = 4.38{pm}0.02, b = 5.90{pm}0.02, c = 8.76{pm}0.03 {AA}, {alpha} = 110{AA}1, {eta} = 96{pm}1; and; {gamma} = 101{pm}1^{circ}.$ There is one molecule in the unit cell. The atomic coordinates were found by means of two-dimensional Fourier projection and ($F_o-F_c$) projection along the a, b and c axes. The structure of p-phenylenediamine dihydrochloride is discussed in relation to the structures of hexamethylenediamine dihydrochloride, hexamethylenediamine dihydroiodide and ethylenediamine dihydrochloride.
