| Acronym | Meaning |
| CIPEA | Comite International Pour L'Etude Des Argiles |
| PT2F | Second-order Perturbation Theory (with) Fock (matrix) |
| SSH | Suppressive Subtraction Hybridization |
| HWC | Hazardous Waste Combustor |
| AQL | Acceptable Quality Levels |
| ACP | Amorphous Calcium Phosphate |
| NOET | NASA Operational Environment Team |
| RHO | Reduced Hamiltonian Orbital Method |
| EPA | Extended Pair Approxn. (in Elec. Cond. Calcn.) |
| EHP | Electron-hole Potential Method |