on the heat capacity of the materials. Comparing structures with the dichloroimidazolate (dcIM) with imidazolate (IM) linkers is instructive to further understand the role of linker functionalization, as the only difference between these structures is replacement of hydrogen atoms on the linker with chlorine. Clearly, replacing the hydrogens with heavier atoms (i.e., chlorine) increases the heat capacity of the material, similar to the simple spring-mass model described above, where the heavy chlorine atoms shift the vibrational frequencies to smaller values, leading to a higher heat capacity per atom.