| Acronym | Meaning |
| UCCD | (spin) Unrestricted Coupled Cluster (with) Double (excitations) |
| CPPI | Cross-polarization-polarization-inversion [NMR] |
| PFEO | Perimeter Free Electron Orbital |
| SLC | SLAC Linear Collider |
| RRNA | Ribosomal Ribonucleic Acid |
| DWS | Drinking Water Standard |
| PCE | Polychromatic Erythrocytes |
| MHC | Major Histocompatibility Complex |
| MEVVA | Metal Vapor Vacuum Arc |
| SCEM | Semiclassical Self-consistent Eikonal Method |