pg. 1 The influence of the Jahn-Teller-effect at Fe 2+ on the structure of chromite at high pressure Atsushi Kyono, ab* Stephen A. Gramsch, b Takamitsu Yamanaka, b Daijo Ikuta, c Muhtar Ahart, b Bjørn O. Mysen, b Ho-kwang Mao, b and Russell J. Hemley b a Division of Earth Evolution Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan b Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, N.W., Washington D.C. 20015-1305, USA c HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Ave., Bldg. 434E, Argonne, Illinois, 60439, USA Correspondence author: A. Kyono Address: Division of Earth Evolution Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan Correspondence e-mail: kyono@geol.tsukuba.ac.jp Phone: +81-29-853-7176, Fax: +81-29-853-7887