#   A       Z       N   Z_calc  N_calc     cn    <rho(A)>
    3.0     2.0     1.0   1.998   0.999   0.500  0.06181
    4.0     2.0     2.0   1.997   1.997   1.000  0.09372
    9.0     4.0     5.0   4.000   4.999   1.250  0.05215
   12.0     6.0     6.0   6.005   6.005   1.000  0.07951
   15.0     7.0     8.0   8.000   9.143   1.143  0.08581
   27.0    13.0    14.0  13.007  14.008   1.077  0.09348
   40.0    20.0    20.0  20.010  20.010   1.000  0.09342
   56.0    26.0    30.0  26.062  30.072   1.154  0.10436
   63.0    29.0    34.0  27.971  32.793   1.172  0.11053
  108.0    47.0    61.0  46.021  59.729   1.298  0.10831
  119.0    50.0    69.0  50.000  68.999   1.380  0.11280
  197.0    79.0   118.0  78.004 116.513   1.494  0.12164