Figure 3a:

Representative internucleosome interaction matrices for 50-nucleosome restrained-loop fibers with −LH, $\frac{1}{2}$LH, +LH, and +LH+Mg²⁺. Local contacts cluster along the diagonal, where fibers show dominant zigzag organization, and simple hairpins are evident by regions perpendicular to the main diagonal. For both systems, divalent ions and linker histones decrease the strength (percentage of occurrence) of higher-order interactions, shown as weaker diagonal hairpins. Additional interaction matrices for other loops sizes are provided in Supporting Information.