Probability distribution of velocity offset between peak velocities of multiple lines with respect to the centroid velocity of NH₂D lines of NH₂D cores. The peak velocity, V_p, is given by the corresponding molecular line noted in upper left corner of each subplot; $V_{\text{c},{\text{NH}}_2\text{D}}$ indicate the centroid velocity of the broad-linewidth component or the narrow-linewidth component of the two-component fits to NH₂D lines (Fig. D.1).