Different types of uncertainties involved in drop-weight measurements of ℎ .# include atmospheric conditions, particle size distribution and shape, presence of crystalline defects, humidity, and even the operator technique. Furthermore, the impact sensitivity depends not only on these macroscopic properties and experimental conditions but also on microscopic properties (e.g., bond-breaking activation energies and energy per molecule), mesoscale properties (e.g., strain and phonon energy transfer mechanics ). Despite these issues, ℎ .# values are very helpful in quantifying the impact sensitivity. Additionally, this plethora of possible influences shows that the prediction of impact sensitivity based on physical properties "remains a challenge". Considering that the stability of a molecule of an energetic material is related to its sensitivity, the latter stems from the chemical character of the materials, which can be accurately investigated by quantum chemical methods. Furthermore, this approach is particularly convenient because the macroscopic property impact sensitivity "is not known to depend directly on intermolecular interactions in bulk", typical hazards of the experimental work are not involved especially on potential new energetic materials, not to say that "imprecise impact sensitivity measurements can provide a false sense of security that might result in fatalities when handling even small quantities of the material". Quantum chemical methods also allows safer screening of a more significant number of potentially greener energetic materials to reduce environmental contamination. Attempts to correlate molecular properties and impact sensitivities have a long history, beginning in the 1970s. These approaches developed models that included the proportion of oxygen atoms in the explosive molecules, molecular structural parameters such as the number of carbon atoms and molecular masses, quantitative structure-property relationships (QSPR) involving structural (e.g., weaker molecular bonds) and energetic (e.g., dissociation energies), among many other properties, known as descriptors in QSPR jargon. Quantum chemical modeling of impact sensitivities, in particular, has quite been quite successful in this regard, especially for a given class category of materials such as nitroaromatics, nitramines, among others.