FISPACT-II group structures
The internal, predefined group structures recognised by FISPACT-II are listed below. The group structures represent the energy boundaries, in eV, which the nuclear data and flux should be accordingly defined.
Note that custom group structures can be defined via the use of GETXS 1 1 option, allowing the user to specify an arbitrary energy bin structure via the enbins input file. This file should give a description of the energy bin structure, followed by the number of groups (i.e. the actual ebins to be used), and then a list of comma-separated ebins+1 energy boundaries in decreasing eV order.