# Electron Impact Cross Sections and Transport Studies of C\({}_{3}\)F\({}_{6}\)[PERSON]
## 3 Results and Discussion  
### Electron Impact Cross Section  
The study of scattering is the first step to determine the insulating performance of any ionized plasma. The species are randomly moving and are free to interact with each other. This leads to both elastic and inelastic collisions. The elastic collisions are the dominant mechanism for power deposition in the plasma and, hence, momentum transfer cross sections are very important inputs for simulations. The main mechanism behind this momentum transfer is neutral collisions. The inelastic collisions are important for the generation of charged species, which might form the reactive fragments in the plasma. However, in the present case, the fraction of these charged fragments was very low when compared to the neutral parent molecule. Hence, scattering cross sections for neutral PMVE with electrons were those that governed, and interactions including ionized species could be ignored without any loss in the accuracy of simulation results.  
The cross section obtained using the methods described in the previous section is shown in Figure 2. The tabulated data is provided in the supplementary material. The cross sections were computed using different basis sets. Since there were no previous data available for low-energy cross sections for PMVE, we compared our DEA cross section with the intensity curve for the generation of OCF\({}_{3}^{-}\). The present peak obtained using the 6-31G basis set matched excellently with the experimental peak at 2.6 eV (please refer to Figure 4 in reference [19]). Hence, we used the cross section obtained using the 6-31 G basis set for transport studies. Our SEP results give a low-energy resonance at 2.9 eV. This can be attributed to the DEA process studied here. The first peak shifted as the first resonance energy changed with different basis sets. The broader peak at energies above 8 eV was due to the excited PMVE and not due to the ground state target.  
Figure 2: Cross section for different scattering processes for electron\(-\)PMVE interaction.  
The ionization cross section obtained using the BEB method shows the typical curve with a maximum around 100-200 eV. The elastic and momentum transfer cross section decreased monotonically as the contribution from various inelastic channels increased. The peak structure in these cross sections is attributed to the resonances, a signature characteristic of low-energy scattering. The excitation cross sections (electronic and rotational) for a number of excited states are also presented in the figure. A total of four electronic excited states and five rotationally excited states were included in the cross section plot. The thresholds for the first four electronically excited states were 5.245, 8.717, 9.397, and 11.013 eV. Among these, the \({}^{3}A_{1}\) state was the dominant channel in the low energy. Further, high-energy Bef excitation cross sections are also shown here. Since the Bef cross section was only determined for the singlet state using QEC, we added the low-energy excited state cross section for the two triplet states and extrapolated it for our transport studies. In the case of rotational excitations, in the very low energy region (\(\leq\)7 eV), the 0 \(\rightarrow\) 1 transition was dominant, and above this energy range, 0 \(\rightarrow\) 4 had the maximum contribution. The contribution from the 0 \(\rightarrow\) 5 transition was negligible throughout the impact energy range.