| Acronym | Meaning |
| DDQRPA | Double Direct Quadratic Random Phase Approximation |
| HESS | High Energy Stereoscopic System |
| HAA | Haloacetic Acid |
| NERC | Natural Environment Research Council (UK) |
| AGCM | Adiabatic Generator Coordinate Method (for Energy Level Calcn.) |
| QTM | Quick-turnaround Method |
| AQDHS | Air Quality Data Handling System |
| DUT | Device Under Test |
| PCR | Polymerase Chain Reaction |
| MP4(DQ) | Moeller-Plesset Perturbation Treatment To Fourth Order In The Space Of Double And Quadruple Substitutions |