1. XANES/NEXAFS with ADF Expert: Mauro Stener - webinar, original slides
ADF: Erik van Lenthe
See also XPS exercise

2. XANES/NEXAFS tips: K-edge
Slater’s Transition State (TS): move half electron from occupied orbital i to virtual a. converge SCF (i)-½(a)+½ and calculate energy differences:
Pragmatic approach: Transition Potential
just remove half electron (i)-½(a)0
Includes core relaxation
Widely used for (metal) K-edges
Basis set: e.g. TZ2P, QZ3P-3DIF
Functional: GGA (e.g. PW91)
Modify / select excitations
Can resolve angularly:
Orientation molecules adsorbed on surface
G. Fronzoni, G. Balducci, R. de Francesco, M. Romeo, M. Stener, J. Phys. Chem. C 116, (2012)

3. Workflow XANES/NEXAFS K-edge (GUI)
Optimize your molecule (e.g. BP-D3(BJ)/DZP)
Change basis set if necessary, (AE for the core electron!)
Model => Spin & Occupations
Remove half an electron from the core of interest (2.0=>1.5)
Check ADFlevels / output to see which orbital
You can also just use AE on the atom of interest, frozen core elsewhere!
Properties: Excitation:AllowedOnly & Delta eps
Set number of excitations (e.g. 100)
Click on the … next to Select Excitations
Select Modify Excitation and set the occupied orbitals
Or the occupied orbital range, but: core relaxation will change energies!
Run
Command-line: Skip 2.-8.
Just set Occupations & Modify Excitations
Example: H2CO O(1s) .adf, .run, (compare with exp) 4.
5.1 .
5.2 . 6. 7. 8.

4. XANES/NEXAFS for L edges
TDDFT necessary for L-edges to include some CI
SOC necessary for L2,3
SOC splits p-levels
Selected (core) excitations
FDMNES, FEFF fails
Functional: LB94
Correct asymptotic behavior
Try hybrids for covalent
I. Alperovich, G. Smolentsev, D. Moonshiram, J.W. Jurss, J.J. Concepcion, T.J. Meyer, A. Soldatov, Y. Pushkar Understanding the Electronic Structure of 4d Metal Complexes: From Molecular Spinors to L-Edge Spectra of a di-Ru Catalyst J. Am. Chem. Soc., (2011).

5. Workflow SOC-TDDFT XANES L2,3-edge4.
Optimize (e.g. SR-BP-D3(BJ)/DZP)
Change basis set & xc (LB94, AE for core e)
Run single point
ADFlevels: Scroll down to find core orbital of interest
Set Properties: Excitation: Spin-Orbit (Perturbative)
Set number of excitations (e.g. 30)
Click on the … next to Select Excitations
Select Modify Excitation and set occupied orbitals
Change functional and basis set? (Hybrid? Model?)
Run
Command-line: Skip 4.-8.
Just Modify Excitations and set Excitations block
Example: TiCl4 2p .adf, .run, (compare with exp) 5. 6. 7. 8.