c2v,        xsec
 -2.0, 0.010591959
-1.75, 0.008972169
 -1.5, 0.007493725
-1.25, 0.006156628
 -1.0, 0.004960881
-0.75, 0.003906480
 -0.5, 0.002993427
-0.25, 0.002221721
  0.0, 0.001591362
  0.1, 0.001378796
  0.2, 0.001188845
  0.3, 0.001021510
  0.4, 0.000876791
  0.5, 0.000754687
  0.6, 0.000655199
  0.7, 0.000578326
  0.8, 0.000524069
  0.9, 0.000492427
  1.0, 0.000483402
  1.1, 0.000496991
  1.2, 0.000533197
  1.3, 0.000592017
  1.4, 0.000673454
  1.5, 0.000777506
  1.6, 0.000904174
  1.7, 0.001053457
  1.8, 0.001225356
  1.9, 0.001419870
  2.0, 0.001637000
 2.25, 0.002278768
  2.5, 0.003061884
 2.75, 0.003986347
  3.0, 0.005052158
 3.25, 0.006259315
  3.5, 0.007607821
 3.75, 0.009097675
  4.0, 0.010728873