Theoretical study of valence photoelectron spectrum of OsO4: A spin-orbit RESC-CASPT2 study

Abstract

Articles you may be interested inStrong electron correlation in UO2 −: A photoelectron spectroscopy and relativistic quantum chemistry study J. Chem. Phys. 140, 094306 (2014); 10.1063/1.4867278 Closed-shell coupled-cluster theory with spin-orbit coupling J. Chem. Phys. 129, 064113 (2008); 10.1063/1.2968136 Spin-orbit configuration interaction study of the electronic structure of the 5 f 2 manifold of U 4 + and the 5 f manifold of U 5 + J. Chem. Phys. 128, 154310 (2008); 10.1063/1.2888560High-order electron-correlation methods with scalar relativistic and spin-orbit corrections Theoretical study of valence photoelectron spectra of Re ( C O ) 5 X ( X = Cl , Br, and I): A spin-orbit DK3 symmetry-adapted cluster/symmetry-adapted cluster-configuration interaction studyThe valence photoelectron spectrum ͑bands from A to E͒ of OsO 4 is studied by second-order complete active space perturbation theory ͑CASPT2͒. The relativistic effects are included by the relativistic elimination of the small components ͑RESC͒ scheme. Spin-orbit coupling is also considered. Both the electron correlation and relativistic effects are significant on the peak position and intensity of valence photoelectron spectrum of OsO 4 . RESC-CASPT2 gives values for the peak position and intensity in reasonable agreement with the resolved photoelectron spectrum data. The state ordering is predicted as 2 T 1 (1t 1 )Ͼ 2 T 2 (3t 2 )Ͼ 2 A 1 (2a 1 )Ͼ 2 T 2 (2t 2 )Ͼ 2 E 2 (1e). Electron correlation shifts all peak positions by 2.5-3.5 eV to the high-energy side. Spin-free relativistic effects shift the band D by 0.8 eV again to the high-energy side due to the stabilization of Os 6s orbital. The present study confirms that the band C arises from the spin-orbit coupling in the ionic 2 T 2 (3t 2 ) state. Under the E band, there are many two-electron shake-up peaks in addition to the two one-electron ionization peaks. The broad feature of the E band is due to the satellite peaks and can be well explained through the introduction of the relativistic effects.

Excited states of OsO4: A comprehensive time‐dependent relativistic density functional theory study

“…To further confirm this finding, we performed a two‐step calculation: After the scalar relativistic SCF calculation converged, the SOC matrix was constructed and diagonalized without further iterations. The so obtained energy levels of the relevant spinors differ by less than 0.05 eV from those by the variational calculation, clearly indicating that the inadequate treatment of the SOC in Ref 24. is due to the chosen empirical one‐electron spin‐orbit operator rather than the state interaction approach.…”

“…Several relativistic calculations have been carried out at both ab initio 5, 10, 24 and density functional11, 25–28 levels of theory. However, the SOC effects were either neglected completely5, 10, 11, 28 or treated inadequately by using an empirically scaled one‐electron spin‐orbit operator 24. The source for the SOC has been disputed26, 27 when interpreting the PE spectrum.…”

Accurate ab initio potential energy curve of F2. II. Core-valence correlations, relativistic contributions, and long-range interactions

“…The code in GAMESS, 17 which we have used, goes back to Nakajima and Hirao 24 and Nakajima et al 25 and was further modified by Fedorov et al 26 Earlier studies 21 of diatomic binding energies had indicated that CASSCF calculations using cc-pVQZ bases yield satisfactory scalar relativistic contributions. To assess the reliability of this choice, we made DK3 calculations with a number of wavefunctions at selected points along the dissociation curve.…”

Recent Advances in Electronic Structure Theory

“…The RESC approach has been applied to various systems in ground and excited states. [106][107][108][109][110][111][112][113] RESC has been known to work well for a number of systems, and recent studies show that RESC gives similar results for the chemical properties as the DKH method, although very large exponents in the basis set can lead to variational collapse in a current RESC approximation, partly because the current implementation includes only the lowest truncation of the O operator. Since the energy gradient of the RESC method is also available currently, 114 we can study the chemical reaction in the heavy element systems.…”