| Acronym | Meaning |
| SADPT | Symmetry-adapted Double Perturbation Theory |
| MTO | Muffin-tin Orbital |
| CGA | Compressed Gas Association |
| ESSP | Eddy Statistics Scientific Panel |
| THM | Transcorrelated Hamiltonian Method |
| FYNES | Fluorescence Yield Near Edge Spectroscopy |
| EEC | European Economic Community |
| MMS | Merged Markush Service |
| TICS | Time Reversal Invariant Closed Shell (type Of Hartree-Fock Wave Function) |
| MMA | Manual Metal Arc Welding |