Notes: Structure and Conformation of Photosynthetic Pigments and Related Compounds 3. Crystal Structure of β-Carotene

The crystal structure of the title compound (C 40 H 56 , M w = 536.8) has been redetermined by X-ray diffraction methods in order to achieve a structure at higher resolution suitable for theoretical calculations. The crystal system is monoclinic, P2 1 /n, a = 7.656(2), b = 9.445(5), c = 23.536(15) Å, β = 93.41(2)°, V = 1698.8(15) Å 3 , Z = 2, D = 1.050 m g/m 3 , 130 K. R = 0.071, R w = 0.076.