O–H related modes (cm⁻¹) in ice and TFSA·nH₂O.

Description	Species
	Ice	n = 0	n = 1 (H3O+)	n = 2 (H5O3+)	n = 4 (H9O4+)
O–H stretch	3215, 3380	3090	2850	3260, 3380	3460
O–H bend	1580	685 (oop), 1185 (ip)a	950 (sym), 1616 (asym)b	1640 (sh),c 1730	1644, 1746
Librations	535–1000		480–830	470–810	370–1040
Translations	20–325		20–300	20–270	20–260

^aoop = out-of-plane S–O–H bend, ip = in-plane S–O–H bend.

^basym = asymmetric bend, sym = symmetric bend.

^csh = shoulder.