Spin-orbit splitting distortion

The authors have interpreted their data using a statistical model, which reveals that the energy gap between the 1 Aj ground state and the lowest of the spin-orbitally split ST2 levels is temperature dependent the form of this temperature dependence changes with x. The model includes spin-orbit coupling, low-symmetry field distortion, covalency, and dynamic as well as static effects of local ligand vibrations. 

Discussion. Copper in Krypton. The absorption spectra of copper atoms Isolated in rare gas matrices have been extensively studied (15-25) and the triplet of bands at 310nm attributed to a number of different causes. These include (1) spin orbit splitting and static axial site distortion (17), (2) multiple matrix sites (18), (3) exciplex formation between the metal and a single matrix atom (19), (4) long range metal-metal interactions (2 ), and (5) Jahn-Teller (JT) effect resulting from matrix cage atom vibrations on the excited metal (21,22,23). The MCD of Cu atoms in the rare gas matrices has recently been reported (24,25) and the results interpreted as consistent with either the distorted site or JT hypotheses (39). 

The CH3S(X ) state is subjected to the Jahn-Teller distortion, and the actual structure for CH3S(X) is expected to have a symmetry [65]. The previous studies, however, indicate that the Jahn-Teller stabilization is small [123] and is substantially smaller than the spin-orbit splitting (259 cm ) [124] for CH3S(X 3/2,i/2) In a lower C, symmetry, transforms as a and the e orbitals are split into orbitals transformed as a and a". The CH3S(X ) ground state has the electronic configuration... 

Moreover, the state is in principle Jahn-Teller unstable, and any such distortion can lead to partial quenching of spin-orbit splittings [28]. 

In Table I, 3D stands for three dimensional. The symbol symbol in connection with the bending potentials means that the bending potentials are considered in the lowest order approximation as already realized by Renner [7], the splitting of the adiabatic potentials has a p dependence at small distortions of linearity. With exact fomi of the spin-orbit part of the Hamiltonian we mean the microscopic (i.e., nonphenomenological) many-elecbon counterpart of, for example, The Breit-Pauli two-electron operator [22] (see also [23]). 

Indeed, in. some cases it is probable that V2 is not ob.served at all, but that the fine. structure arises from term splitting due to spin-orbit coupling or to distortions from regular octahedral symmetry. 

Foyt et al. [137] interpreted the quadrupole-splitting parameters of low-spin ruthenium(II) complexes in terms of a crystal field model in the strong-field approximation with the configuration treated as an equivalent one-electron problem. They have shown that, starting from pure octahedral symmetry with zero quadrupole splitting, A q increases as the ratio of the axial distortion to the spin-orbit coupling increases. 

For the temperature range we are interested in, spin-orbit coupling effects can be neglected compared with the level splitting owing to a particular distorted arrangement of point charges around an Fe ion. 

Liehr has shown (142) that the orbital degeneracy of the ground state in a tetrahedral nickel(II) complex may be lifted by spin-orbit coupling. This means that these complexes may not be liable to Jahn-Teller distortion as has been thought for some time. Such coupling would also have the effect of splitting all transitions into several components, the exact number... 

Values for the spin Hamiltonian are given in Table XIV. The 5D state of d6 has three orbital states for the ground state in octahedral symmetry. Since these three states are connected by the spin-orbit coupling, the spin-lattice-relaxation time is quite short and the zero-field splitting very large. In a distorted octahedral field the large zero-field distortion makes detection of ESR difficult. In the case of ZnF2 the forbidden AM = 4 transition was measured and fitted to Eq. (164). 

---