(a) The amplitudes and orientations of backbone 15NH CSA tensors for G89 (left) and E98 (right) in HIV-1 CA protein with respect to the molecular frame, for the individual structures along the MD trajectory at t = 0, 1, 2, and 3 ns (from top to bottom, respectively). (b–d) Plots of the relative angles between the principal components of the 15N CSA tensor, δii, and the N-H bond, rN-H. (e–g) Euler angles for the backbone 5NH CSA tensors in the molecular frame. The CSA parameters and relative tensor orientations were calculated by QM/MM (at the DFT level) for the individual structures along the MD trajectory as a function of time, as shown for G89 (black triangles) and E98 (red circles).