Figure 7: Absorption lines derivatives, 𝑑 𝜒 / 𝑑 𝐻 d c , resulting from the computer simulations in the case when magnetic anisotropy axes orientations represent a chain-like structure of 𝑁 = 4 0 magnetic nanoparticles oriented into 𝑧 -direction, chain-like structure of 𝑁 = 4 0 nanoparticles oriented into 𝑥 -direction, or they represent a random cluster consisting of 𝑁 = 8 0 and 𝑁 = 2 0 0 , respectively. The parameters of the computer simulation have only a qualitative meaning and they have been taken the same as in [5].