Table 1.

The 4.2 K Mössbauer parameters of AlkB

Species	Fraction of total Fe*	ΔEQ, mm/s	δ,† mm/s
Fe(III)–Fe(III)	≈0.6 [0.55–0.62]	1.70 (5)‡	0.55 (3)
		1.13 (5)	0.51 (3)
Fe(II)–Fe(II)		2.4–3.3§	1.05–1.15§
Ferrous SA	≈0.20 [0.15–0.22]	3.2	1.1
Ferric SB¶	≈0.20 [0.18–0.22]	0.7	0.5

^*Percentages given are for the sample of Figs. 2A and 3A. Samples from two other preparations had less Fe(III)–Fe(III) (≈35% and 50%). Numbers in square brackets give an estimated range of fractions compatible with our data. 

^†Quoted relative to Fe metal at 298 K. 

^‡Numbers in parentheses represent estimated uncertainties in the last significant digit. 

^§Range of parameters; see comments in the text. 

^¶Monomeric high-spin Fe(III) of Fig. 3B; the magnetic hyperfine tensor used for simulation was A = −(27, 28, 29) MHz, ΔE_Q = 0.7 mm/s, and δ = 0.45 mm/s. The use of an anisotropic A tensor provides the flexibility to account for the possible presence of multiple species with slightly different A values.