| Acronym | Meaning |
| CRHF | Complex-restricted Hartree-Fock |
| LAOS | Light Amplifying Optical Switch |
| FNO | Frozen Natural Orbital |
| REE | Rare Earth Element(s) |
| PIAMS | Photoionization Aerosol Mass Spectrometry |
| HFP | Hartree-Fock (plus) Pauli (terms) |
| GIAXRD | Grazing Incidence Angle X-ray Diffraction |
| XRMF | X-ray Microfluorescence |
| LWR | Light-water Reactor |
| ESRIN | European Space Research Institute |