  We have studied atomic structures of a-sexithienyl (6T) films grown on
Cu(110) by near-edge x-ray absorption fine structure (NEXAFS). A
one-dimensional (1D) ordered structure of 6T with its molecular long axis
parallel to the Cu[001] direction could be fabricated by deposition at 300 K
and subsequent annealing at 360 K. Polarization and azimuth-dependent NEXAFS
revealed the formation process of the 1D structure and showed the molecular
orientation in the in-plane direction directly. We propose here a method to
obtain the orientation distribution function of molecules using NEXAFS.
