Abstract
The crystal structure of ethylenediamine dihydrochloride has been determined by the two-dimensional Patterson methods and refined by two-dimensional Fourier syntheses. The unit cell dimensions are a = 4.44${\pm}$0.02, b = 6.88${\pm}$0.02, c = 9.97${\pm}$0.02 ${\AA}$, ${\beta}$ = 92${\pm}$$1^{\circ}$. The space group is $P2_1_{/c}$. The carbon and nitrogen atoms in the ethylenediamine itself lie on one plane and its structure has a trans-form with a centre of symmetry in it, and C-C distance of 1.54 ${\AA}$, C-N distance of 1.48${\AA}$ and C-C-N bond angle of $109.07^{\circ}$. The molecules are linked by N-H${\cdots}$Cl hydrogen bonds with distance of 3.14, 3.16 and 3.22 ${\AA}$ forming three dimensional network. The values of reliability factor for F(okl), F(hol) and F(hko) are 0.11, 0.10 and 0.09 respectively.