c2v,        xsec
 -2.0, 0.016050897
-1.75, 0.013642660
 -1.5, 0.011445327
-1.25, 0.009458902
 -1.0, 0.007683386
-0.75, 0.006118777
 -0.5, 0.004765077
-0.25, 0.003622284
  0.0, 0.002690399
  0.1, 0.002376699
  0.2, 0.002096745
  0.3, 0.001850536
  0.4, 0.001638071
  0.5, 0.001459353
  0.6, 0.001314379
  0.7, 0.001203151
  0.8, 0.001125668
  0.9, 0.001081930
  1.0, 0.001071937
  1.1, 0.001095690
  1.2, 0.001153188
  1.3, 0.001244431
  1.4, 0.001369419
  1.5, 0.001528153
  1.6, 0.001720632
  1.7, 0.001946856
  1.8, 0.002206825
  1.9, 0.002500540
  2.0, 0.002828000
 2.25, 0.003794285
  2.5, 0.004971479
 2.75, 0.006359579
  3.0, 0.007958589
 3.25, 0.009768505
  3.5, 0.011789328
 3.75, 0.014021060
  4.0, 0.016463699