| Acronym | Meaning |
| SRS | Symmetrized Rayleigh-Schroedinger (perturbation Theory) |
| HARA | Hazard Assessment By Risk Analysis |
| CI-HY | Configuration Interaction-Hylleraas |
| IBI | Index Of Biotic Integritypar |
| FMTBA | Fitted Modified Tight-binding Approxn. |
| PTR | Photothermal Radiometry |
| OSCCM | Open-shell Coupled-cluster Method (in Electronic Property Calcn.) |
| ISHM | International Society For Hybrid Microelectronics |
| HEM | Heat-exchanger Method (in Manuf. Of Crystalline Silicon) |
| CTTS | Classical T Tauri Star |