Vn (from Palik II: p. 308)
ANGSTROMS
NK
     2066       1.82      1.74
     2254       1.98      1.7
     2480        2.1      1.64
     2755       2.19      1.56
     3100        2.2      1.54
     3542       2.18      1.58
     4133       2.13      1.7
     4959       2.17      1.98
     6199       2.35      2.47
     8266       2.73      2.92
    12399       3.19      3.66
    24797       4.23      6.13