There are two frequent sources to create these errors:
1: If one uses the output of racah to plot with
old_racah ni2.rac_out and one uses a symmetry lower than cubic,
there is a mistake in the plotting programme. The plotting program
is reading the output of TT-RAC and cannot find the information it needs.
This can be solved by making small changes to the output.
By changing "-)" to "- )" throughout the file ni2.rac_out,
the error should disappear.
This error does not occur for output of TT-BAN.
2: In general, if a spectrum contains zero intensity, the programme stops with a floating point error. This occurs also if one calculates an MCD spectrum and the negative axis is larger than the positive axis.