The only motion is in the torsion angle about the rotation axis.
Assuming the rotation axis is the z-axis, the rotation matrix is defined as
The frame order matrix is
The surface normalisation factor is
The 1 degree frame order matrix with tensor rank-2 is
The 2 degree frame order matrix with tensor rank-4 is
where sσ = sincσmax and s2σ = sinc(2σmax). The active matrix elements which are not zero due to symmetries, in Kronecker product double indices from 0 to 8, are
The frame order matrix element simulation script from Section 16.2, page was used to compare the implementation of equations 16.13 and 16.15 above. Frame order matrix Daeg(1) and Daeg(2) values were both simulated and calculated, both within and out of the motional eigenframe. The in-frame Daeg(1) and Daeg(2) values are shown in figure 16.1. The out-of-frame Daeg(1) and Daeg(2) values are shown in figure 16.2.
The relax user manual (PDF), created 2019-03-08.