𝛿𝜔{𝐼 1𝑧 -𝐼 2𝑧 } Thus, we neglect any spin evolution in the free form of H 2 and consider only a single term in , which ℋ 𝑏 originates from the frequency difference of the two protons in the bound form. After that, we go to the Liouville space and specify and as column vectors with 16 elements (corresponding to a two-spin 𝜎 𝑓 𝜎 𝑏 system). In this representation, are written as superopeartors, which are matrices, whereas ℋ 𝑓,𝑏 16 × 16 the relaxation superoperators are also matrices . To specify all elements of we use the model of Γ 𝑓,𝑏 Γ 𝑓,𝑏 partly correlated fluctuating local fields, and , experienced by the two spins. This means, 𝐁 (𝑡) 𝐁 (𝑡) that we use the same method as before but averaging of the local fields is performed using the following expressions (here is the auto-correlation function of the process): 𝑔(𝜏) 〈𝐵 𝑖 (𝑡)𝐵 𝑗 (𝑡 + 𝜏)〉 = 〈𝐵 2 〉𝛿 𝑖𝑗 𝑔(𝜏), 〈𝐵 𝑖 (𝑡)𝐵 𝑗 (𝑡 + 𝜏)〉 = 〈𝐵 2 〉𝛿 𝑖𝑗 𝑔(𝜏), 〈𝐵 𝑖 (𝑡)𝐵 𝑗 (𝑡 + 𝜏)〉 = 𝐶 × 〈𝐵 2 〉𝛿 𝑖𝑗 𝑔(𝜏) Hence, different components are non-correlated while the amplitudes and auto-correlation functions of the two fields are the same. The parameter determines the effective relaxation rate in the system in 〈𝐵 2 〉 the free or bound form, and . Specifically, in the limiting narrowing case, each T 1 -value is related to 𝑇 𝑓