| Autor: |
Kasper JM; Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States., Lestrange PJ; Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States., Stetina TF; Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States., Li X; Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States. |
| Abstrakt: |
X-ray absorption spectroscopy is a powerful technique to probe local electronic and nuclear structure. There has been extensive theoretical work modeling K-edge spectra from first principles. However, modeling L-edge spectra directly with density functional theory poses a unique challenge requiring further study. Spin-orbit coupling must be included in the model, and a noncollinear density functional theory is required. Using the real-time exact two-component method, we are able to variationally include one-electron spin-orbit coupling terms when calculating the absorption spectrum. The abilities of different basis sets and density functionals to model spectra for both closed- and open-shell systems are investigated using SiCl 4 and three transition metal complexes, TiCl 4 , CrO 2 Cl 2 , and [FeCl 6 ] 3- . Although we are working in the real-time framework, individual molecular orbital transitions can still be recovered by projecting the density onto the ground state molecular orbital space and separating contributions to the time evolving dipole moment. |
