Bismuth

Table 1. Bi 4f7/2 binding energy data collated from [1].
Bi 4f7/2 - 4f5/2 splitting = 5.31 eV.

R.S.F. Bi 4f = 9.14, Bi 4f7/2 = 5.223

Reference:
[1] C.D. Wagner, A.V. Naumkin, A. Kraut-Vass, J.W. Allison, C.J. Powell, J.R.Jr. Rumble, NIST Standard Reference Database 20, Version 3.4 (web version) (http:/srdata.nist.gov/xps/) 2003.