Another interesting aspect of Fig. is the distinct stress-strain response curve for when ψ = 90 • . Although it has an early sharp dip in stress when ϵ = 24%, its stress reaches a negative value and then returns to a linear stress-strain curve when further strain is appliedcontrary to the expected material behavior, the negative stress at ϵ = 24% denotes compressive strain despite simulated tensile strain. We also see a similar dip in values for within the elastic energies graph. When looking at our model near this strain level, we see that there is a phase transition, as shown within Fig. . In such, the layer reorients itself to a nearly undeformed structure similar to when ψ = 0 • . During the phase change, one P-P bond breaks and another is formed, relieving the stress on the system. Discussion of the mechanical basis behind this reorientation will be further discussed within this study. Using the stress-strain curve plotted within Fig. , we find the values of strength (σ max ) and Young's modulus (E). Strength is defined as the material resistance to deformation, and Young's modulus defines the material's stiffness and linear elasticity. In order to calculate strength, we simply find the maximum stress within each curve. To find Young's modulus, for every angle's stressstrain curve, we fit a 4th degree polynomial. This degree is chosen because it properly fits the curve without overfitting. The polynomial can then be expressed as