(n, 2n) reaction cross-section data based on tensor model

The name of the txt file, e.g. 2021c29063.txt, means that the cross-section data is for the nuclide Z=29, A=63. The first column in the txt file means the neutron incident energy En, the third column in the txt file means the cross-section σ, the fourth column in the txt file means the error for the cross-section err_σ.

The 'datatest.txt' file is the data for the ratio between tensor model calculations and EXFOR data. The first column in the txt file means the neutron incident energy En, the sixth column in the txt file means the ratio σ_BGCP/σ_EXFOR, and the seventh column means the tensor model cross-section σ.