3. Theoretical study of the electronic states of newly detected dications. Case of MgS2+ AND SiN2+
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Toufik Khairat
Abstract
The dications MgS2+ and SiN2+, experimentally observed by mass spectroscopy, are theoretically studied here. The potential energy curves of the electronic states of the two dications MgS2+ and SiN2+ are mapped and their spectroscopic parameters determined by analysis of the electronic, vibrational and rotational wave functions obtained by using complete active space self-consistent field (CASSCF) calculations, followed by the internally contracted multi-reference configuration interaction (MRCI)+Q associated with the AV5Z correlation consistent atomic orbitals basis sets. In the following, besides the characterization of the potential energy curves, excitation and dissociation energies, spectroscopic constants and a double-ionization spectra of MgS and SiN are determined using the transition moments values and Franck-Condon factors. The electronic ground states of the two dications appear to be of X3Σ− nature for MgS2+ and X4Σ− for SiN2+ and shows potential wells of about 1.20 eV and 1.40 eV, respectively. Several excited states of these doubly charged molecules also depicted here are slightly bound. The adiabatic double-ionization energies were deduced, at 21.4 eV and 18.4 eV, respectively, from the potential energy curves of the electronic ground states of the neutral and charged species. The neutral molecules, since involved, are also investigated here. From all these results, the experimental lines of the mass spectra of MgS and SiN could be partly assigned.
Abstract
The dications MgS2+ and SiN2+, experimentally observed by mass spectroscopy, are theoretically studied here. The potential energy curves of the electronic states of the two dications MgS2+ and SiN2+ are mapped and their spectroscopic parameters determined by analysis of the electronic, vibrational and rotational wave functions obtained by using complete active space self-consistent field (CASSCF) calculations, followed by the internally contracted multi-reference configuration interaction (MRCI)+Q associated with the AV5Z correlation consistent atomic orbitals basis sets. In the following, besides the characterization of the potential energy curves, excitation and dissociation energies, spectroscopic constants and a double-ionization spectra of MgS and SiN are determined using the transition moments values and Franck-Condon factors. The electronic ground states of the two dications appear to be of X3Σ− nature for MgS2+ and X4Σ− for SiN2+ and shows potential wells of about 1.20 eV and 1.40 eV, respectively. Several excited states of these doubly charged molecules also depicted here are slightly bound. The adiabatic double-ionization energies were deduced, at 21.4 eV and 18.4 eV, respectively, from the potential energy curves of the electronic ground states of the neutral and charged species. The neutral molecules, since involved, are also investigated here. From all these results, the experimental lines of the mass spectra of MgS and SiN could be partly assigned.
Chapters in this book
- Frontmatter i
- Preface of the Book of Proceedings of the Virtual Conference on Computational Science (VCCS-2016) v
- Contents vii
- List of contributing authors xi
- 1. Addressing the challenges of standalone multi-core simulations in molecular dynamics 1
- 2. Optical and magnetic properties of free-standing silicene, germanene and T-graphene system 23
- 3. Theoretical study of the electronic states of newly detected dications. Case of MgS2+ AND SiN2+ 71
- 4. Analytical Solution of Pantograph Equation with Incommensurate Delay 93
- 5. Computational chemistry applied to vibrational spectroscopy: A tool for characterization of nucleic acid bases and some of their 5-substituted derivatives 117
- 6. Mechanism of nucleophilic substitution reactions of 4-(4’-nitro)phenylnitrobenzofurazan ether with aniline in acetonitrile 153
- 7. Computational methods in preformulation study for pharmaceutical solid dosage forms of therapeutic proteins 163
- 8. Computational Investigation of Cationic, Anionic and Neutral Ag2AuN (N = 1–7) Nanoalloy Clusters 173
- 9. Evacuation simulation using Hybrid Space Discretisation and Application to Large Underground Rail Tunnel Station 191
- 10. DFT study of anthocyanidin and anthocyanin pigments for Dye-Sensitized Solar Cells: Electron injecting from the excited states and adsorption onto TiO2 (anatase) surface 205
- 11. Elemental Two-Dimensional Materials Beyond Graphene 219
- Index 229
Chapters in this book
- Frontmatter i
- Preface of the Book of Proceedings of the Virtual Conference on Computational Science (VCCS-2016) v
- Contents vii
- List of contributing authors xi
- 1. Addressing the challenges of standalone multi-core simulations in molecular dynamics 1
- 2. Optical and magnetic properties of free-standing silicene, germanene and T-graphene system 23
- 3. Theoretical study of the electronic states of newly detected dications. Case of MgS2+ AND SiN2+ 71
- 4. Analytical Solution of Pantograph Equation with Incommensurate Delay 93
- 5. Computational chemistry applied to vibrational spectroscopy: A tool for characterization of nucleic acid bases and some of their 5-substituted derivatives 117
- 6. Mechanism of nucleophilic substitution reactions of 4-(4’-nitro)phenylnitrobenzofurazan ether with aniline in acetonitrile 153
- 7. Computational methods in preformulation study for pharmaceutical solid dosage forms of therapeutic proteins 163
- 8. Computational Investigation of Cationic, Anionic and Neutral Ag2AuN (N = 1–7) Nanoalloy Clusters 173
- 9. Evacuation simulation using Hybrid Space Discretisation and Application to Large Underground Rail Tunnel Station 191
- 10. DFT study of anthocyanidin and anthocyanin pigments for Dye-Sensitized Solar Cells: Electron injecting from the excited states and adsorption onto TiO2 (anatase) surface 205
- 11. Elemental Two-Dimensional Materials Beyond Graphene 219
- Index 229
