By name: spectroscopy description: Spectroscopy Simulation (2 sub-skills: raman-ir, xas-xanes)
Spectroscopy Simulation
Overview
Skills for computing spectroscopic observables from first principles: vibrational spectra (IR, Raman) and core-level X-ray absorption spectra (XAS/XANES). These connect atomistic simulations to experimental measurements.
Sub-skills
| Skill | Path | Description |
|---|---|---|
| Raman & IR Spectroscopy | raman-ir/ |
Compute infrared and Raman spectra from Gamma-point phonons. Uses QE ph.x or MACE + finite differences. Includes Born effective charges, dielectric tensors, and Lorentzian broadening. |
| XAS/XANES Spectroscopy | xas-xanes/ |
Simulate X-ray absorption near-edge structure using QE xspectra.x. Core-hole pseudopotential approach for K-edge and L-edge spectra. |
Typical Workflow
- Relax structure with QE
pw.xor MACE. - IR/Raman: Compute Gamma-point phonons, extract intensities, plot spectra.
- XAS/XANES: Run core-hole SCF, then
xspectra.xfor absorption cross-section.
Prerequisites
# QE binaries: pw.x, ph.x, pp.x, dynmat.x, xspectra.x
# Python: ase, pymatgen, phonopy (pip install phonopy), numpy, scipy, matplotlib
# MACE: mace-torch (for finite-difference approach)