Table 1.

EXAFS curve-fitting parameters for 5 and 7.^a

Cmpd	Bond	N	R	σ	ΔE0	F
5	Se–C	2	1.957(5)	0.0021(4)	−6(1)	0.6337
7	Se–C	2	1.955(4)	0.0024(2)	−6.3(9)	0.5540

^aCoordination numbers N, interatomic distances R (Å), Debye-Waller factors (the mean-square deviations in interatomic distance) σ² (Ų), and threshold energy shifts ΔE₀ (eV). The values in parentheses are the estimated standard deviations in the last digit obtained from the diagonal elements of the covariance matrix. The fit-error function F is defined by $F=\sqrt{\sum k^6{\left(\chi {(k)}_{\mathit{calcd}}-\chi {(k)}_{\text{expt}}\right)}^2/\sum \chi {(k)}_{\text{expt}}^2}$ where χ(k) are the EXAFS oscillations and k is the photo-electron wave number given by $k=\sqrt{\frac{2m_e}{{\hslash }^2}(E-E_0)}$.