Performance of theoretical methods and basis sets on the molecular structure, atomisation and ionisation energies, electron affinity, and vibrational spectrum of silylene

Abstract

This work compares the performance of theoretical methods and basis sets on the molecular structure, atomisation and ionisation energies, electron affinity, and vibrational spectrum of silylene. Silylene, its cation and anion have been studied in 1 A 1 , 2 A 1 and 2 B 1 states, respectively, in the gas phase and C 2v symmetry. The methods considered are second-order Møller-Plesset perturbation theory (MP2), the density functional theory (DFT), Gaussian-2 (G2) and complete basis set methods (CBS-4M and CBS-Q). The basis sets used are 6-31G(d,p), 6-311G(d,p), 6-31++G(d,p) and 6-311++G(d,p). The functional used for the DFT method is B3LYP. Silylene and its cation and anion have been optimised using the MP2 and DFT methods and the named basis sets. Single-point energy calculations (G2, CBS-4M and CBS-Q) were performed using MP2/6-311++G(d,p) structures and these energies have been used to calculate atomisation energy, ionisation energy and adiabatic electron affinity. Frequency calculations were also done and the raw vibrational frequencies were assigned. It is interesting to note the close similarity between the predicted parameters and some of the available literature values. The results obtained are consistent and converge with different basis sets with improved size and quality. However, the parameters obtained are very much methoddependent.

Molecular structure, atomization energy, ionization energy, electron affinity and vibrational spectrum of SiX2(X = F, Cl, Br, I) by theoretical methods

“…In continuation with our work [20], this article aims to report some properties namely molecular structure, atomization energy, ionization energy, electron affinity and infrared vibrational spectra of silicon dihalides, SiX 2 (X ¼ F, Cl, Br, I), by different theoretical methods. In the current investigation, the neutral silicon dihalides have been considered both in the 1 A 1 singlet and 3 B 1 triplet states.…”

“…In a previous communication [20], we compared the performance of theoretical methods and basis sets on the molecular structure, atomization energy, ionization energy, electron affinity and vibrational spectra of silylene. The methods considered were Møller-Plesset perturbation theory (MP2), density functional theory (DFT), Gaussian-2 (G2) and complete basis set methods (CBS-4 and CBS-Q).…”

Electron-impact cross sections ofSiH2using theR-matrix method at low energy

“…Silylene can dissociate to produce amorphous or hydrogenated amorphous silicon, which has applications in device fabrication [14]. The low-energy states of SiH 2 have been studied experimentally and theoretically [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. The modeling and characterization of plasma-based processes require accurate knowledge of cross-section data [32].…”