where 𝑁 = -𝑞 is the number of electrons in each shell. To take into account the long-range dependence of the atomic charges on the chemical structure, charge equilibration (QEq) was applied. QEq provides the total atomic charges (𝑞 𝑖 = 𝑞 𝑖 𝑐𝑜𝑟𝑒 + 𝑞 𝑖 𝑣𝑎𝑙 ) by minimizing the following energy expression: