Theoretical Spectroscopy of GeSi below 30 000 cm−1: A Predictive Study

Electronic states and spectroscopic properties of GeSi

“…The nature of the ground state of group IVA diatomics has been discussed by Sefyani et al [21] on the basis of a competition between orbital energies and Coulombic effects. The computed ground-state bond length of GeSi is 0.017 Å shorter than the value reported by Sefyani and co-workers [26,27]. However, the present r e value is closer to the MRCI estimated value of Ueno et al [29], while the local spin-density calculations [25] reported a value of 2.3389 Å.…”

“…Sefyani et al [26] calculated a value of 800 cm À1 from their MRCI studies, while the local spin-density calculations predicted 887 cm À1 . However, the CCSD(T) estimated transition energy is somewhat lower in magnitude.…”

Molar atomization enthalpies and molar enthalpies of formation of GeSi, GeSi2, Ge2Si, and Ge2Si2by Knudsen-effusion mass spectrometry

“…The bending force constant for GeSi 2 and Ge 2 Si was assumed to be one-tenth of the Ge-Si stretching force constant. The ring-puckering force constant for Ge 2 Si 2 (23) were employed for GeSi, while the excited state wavenumbers of 400 cm −1 (multiplicity=3) and 3000 cm −1 , predicted values for Si 3 , (28,29) and Ge 3 , (30) were assumed for both GeSi 2 and Ge 2 Si. In the case of Ge 2 Si 2 , an excited-state wavenumber of 4000 cm −1 (multiplicity=3) above the electronic ground state was assumed, by analogy with the values predicted for Si 4 , (31) and Ge 4 .…”

“…The Si-Si bond length was assumed to be 2.25·10 −10 m, which is the experimental value for Si 2 , (26) and the Ge-Ge bond length was taken as 2.42·10 −10 m, which is the predicted value for Ge 2 . (27) The vibrational wavenumbers: 387 cm −1 (for GeSi), (23) 512 cm −1 (for Si 2 ), (26) and 343 cm −1 (for Ge 2 ), (27) were used to obtain the stretching force constants for the bonds Ge-Si, Si-Si, and Ge-Ge. The bending force constant for GeSi 2 and Ge 2 Si was assumed to be one-tenth of the Ge-Si stretching force constant.…”

“…(21,22) The Ge-Si bond length for all structures was taken as 2.36·10 −10 m, the same as that predicted for GeSi. (23) The Wilson GMAT/FMAT procedure (24,25) was used to estimate the vibrational wavenumbers for GeSi 2 , Ge 2 Si, and Ge 2 Si 2 . The Si-Si bond length was assumed to be 2.25·10 −10 m, which is the experimental value for Si 2 , (26) and the Ge-Ge bond length was taken as 2.42·10 −10 m, which is the predicted value for Ge 2 .…”