Panel (a): AM (red line) between magnetic fields and velocity gradients concerning the time since self-gravity is turned on (0 Myr), using the subsonic A2 simulation set. Blue line indicates the total gravitational energy in each cube. Panel (b): correlation of total gravitational energy and the mean convergence of the 3D velocity field, using subsonic A2 simulations. Panel (c): variation of total kinetic energy, magnetic field energy, and gravitational energy for A2 simulations. Panel (d): AM of the 3D magnetic field angle and 3D velocity angle for A2 simulations.