1. Hashimoto Polymer Phasing Project, ERATO, Japan Science and Technology Corporation, Keihan-na Plaza, 1-7 Hikari-dai, Seika, Kyoto 619-02, Japan, Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606, Japan, and Departments of Physics and Nuclear Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139