| Acronym | Meaning |
| PRDDO | Partial Retention Of Diatomic Differential Overlap |
| CS | Centrifugal Sudden (approximation) |
| LUCO | Lowest Unoccupied Crystal Orbital |
| CSF | Configuration Spin Function (a Wave Function) |
| ADMI | American Dye Manufacturers Institute |
| CLOS | Common Lisp Object System (language) |
| APCD | Air Pollution Control District |
| RS | Rayleigh Schroedinger (perturbation Theory) |
| ECAP | Energy-compensated Atom Probe |
| CDPT | Constant Denominator Perturbation Theory |