What you are seeing are the files associated with Nastran explicit nonlinear solution (sol700).
You can find documentation for this in the Nastran documentation. It does require a different license to the linear solution.
It is based on Dytran but these files (in the Nastran folders) do not provide a standalone Dytran install. The full install of Dytran is available on the solution download center as a separate product and has a different licensing set to Nastran.