mdtraj.compute_chi2¶

mdtraj.compute_chi2(trajectory, opt=True)¶

Calculate the chi2 torsions of a trajectory. chi2 is the second side chain torsion angle formed between the corresponding 4 atoms over the CB-CG axis.

Parameters:	trajectory : Trajectory Trajectory for which you want dihedrals. opt : bool, default=True Use an optimized native library to calculate angles.
Returns:	indices : np.ndarray, shape=(n_chi, 4) The indices of the atoms involved in each of the chi dihedral angles angles : np.ndarray, shape=(n_frames, n_chi) The value of the dihedral angle for each of the angles in each of the frames.