The crystal structure of ( E )-doxepin hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data, optimized density functional techniques. crystallizes in space group P 2 1 / a (#14) with = 13.78488(7), b 8.96141(7), c 14.30886(9) Å, ? 96.5409(5)°, V 1756.097(12) Å 3 , Z 4. There is strong discrete hydrogen bond between the protonated nitrogen atom chloride anion...