We fragmented the molecular moieties purely based on chemical intuitions (e.g. along the functional groups). Apart from ethene, ethyne and water, all monomers are subjected to fragmentation. As an example, the partitioning of AcNH 2 results in two fragments, -CH 3 and -CONH 2 (Fig. ). The fragments are then capped at the vacant site with H atoms to keep the charge and spin multiplicity unaltered. The polrizability tensor is computed for these fragments subsequently. Note that a balance between number of fragments and accuracy is imperative from the computational point-of-view. Later in this section, effect of fragmentation and the associated errors are discussed in details. The monomer fragmentation is done as follows.