General formalism for vibronic Hamiltonians in tetragonal symmetry and beyond Supporting Information Riley J. Hickman, Robert A. Lang, and Tao Zeng * Department of Chemistry, Carleton University, Ottawa, Ontario, K1S5B6, Canada E-mail: toby.zeng@carleton.ca List of Figures List of Tables S1 Constraints on expansions in Table 2 in the main text to give the appropriate ( χ C 4 =1,χ I ) .................................... S5 S2 Constraints on expansions in Table 3 in the main text to give the appropriate ( χ C 4 = -1,χ I ) ................................... S6 S3 Constraints on expansions in Table 4 in the main text to give the appropriate ( χ C 4 = i, χ I ) . ................................... S6 S1 Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics. This journal is © the Owner Societies 2018