2003/01/18 by Cheolbeom Bae, Young‐Kyu Han, Yoon Sup Lee · 2 citations
Chemistry · Physics and Astronomy · Chemical Engineering · #Inorganic Fluorides and Related Compounds #Advanced Chemical Physics Studies #Ammonia Synthesis and Nitrogen Reduction #Relativistic quantum chemistry #Bond length #Scalar (mathematics) #Atomic physics #Electron #Molecular geometry #Ionic bonding #Valence electron #Physics #Chemistry #Spin–orbit interaction #Spin (aerodynamics) #Molecular vibration #Electronic correlation #Molecule #Molecular physics #Condensed matter physics #Ion #Quantum mechanics #Geometry #Thermodynamics
paper · doi:10.1021/jp026531m
openalex publication_date 2003/01/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/16
Spin−orbit and scalar relativistic effects on geometries, vibrational frequencies, and energies for group 17 fluorides EF 3 (E = I, At, and element 117) are evaluated with two-component methods using relativistic pseudopotentials and effective one-electron spin−orbit operators. The inclusion of relativistic effects makes the D 3 h structure of (117)F 3 a stable local minimum, whereas IF 3 and AtF 3 retain C 2 v local minima even with relativistic effects. The valence shell electron pair repulsion model is not appropriate to explain the molecular structure of (117)F 3 . The geometries of EF 3 (E = I, At, and element 117) molecules are optimized at the HF level with and without spin−orbit effects. Spin−orbit interactions elongate the bond lengths and decrease the harmonic vibrational frequencies. In the case of AtF 3, spin−orbit interactions increase the bond lengths by 0.044 and 0.023 Å for and, respectively. Spin−orbit effects widen the bond angle of C 2 v structures of IF 3 and AtF 3, i.e., spin−orbit effects diminish the second-order Jahn−Teller term. The bond angle α e of AtF 3 increases by 3.9° due to spin−orbit interactions in addition to the increase of 4.8° by scalar relativistic effects. For (117)F 3, spin−orbit effects increase the bond length by 0.109 Å. The spin−orbit interactions stabilize (117)F 3 by a significant margin (∼1.2 eV). This stabilization of the molecule compared with open p-shell atoms is quite unusual. Enhanced ionic bonding may be responsible for this stabilization because the electronegative F atom can effectively polarize or attract electrons from the destabilized 7p 3/2 spinors of element 117 due to huge spin−orbit splitting of 7p.