1. M. I. Eremets and T. C. Kobayashi, Research Center for Materials Science at Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531, Japan. K. Shimizu, Department of Physical Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan. K. Amaya, Department of Physical Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan, and Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai,...