pg. 1 Ab initio quantum chemical investigation of arsenic sulfide molecular diversity from As 4 S 6 and As 4 Atsushi Kyono 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 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