| Acronym | Meaning |
| UVCS | UV Coronagraph Spectrometer |
| UVP | Ultrasonic Vibration Potential |
| UVPES | Ultraviolet Photoelectron Spectroscopy |
| UVPS | Ultraviolet Photoelectron Spectroscopy |
| UVRR | UV Resonance Raman Spectroscopy |
| UW-PG | Uniformly Weighted Planar Grid (method In Calcns. Of Electron-momentum Distributions) |
| UXO | Unexploded Ordnance |
| VA-HOMO | Vibrationally Active HOMO |
| VA-LUMO | Vibrationally Active LUMO |
| VACE | Vacancy Affinity Capillary Electrophoresis |
| VACSY | Variable-angle Correlation Spectroscopy |
| VAD | Vacuum Arc Degassing |
| VAD | Vapor Axial Deposition |
| VADW | Vibrationally-adiabatic Distorted-wave Method |
| VAFTAD | Volcanic Ash Forecast Transport And Dispersion |
| VAH | Volatile Aromatic Hydrocarbon(s) |
| VALE | Vacuum Atomic Layer Epitaxy |
| VAM | Valid Analytical Measurement |
| VAMAS | Versailles Project On Advanced Materials And Stds. |
| VAMO | Variational Alternant Molecular Orbital |
| VAP | Valence Alternation Pair (bonding Configuration Model) |
| VAR | Vacuum Arc Remelting |
| VARTM | Vacuum Assisted Resin Transfer Molding |
| VASE | Variable Angle Spectroscopic Ellipsometry |
| VASP | Vienna Ab Initio Simulation Package |
| VASS | Variable Angle Sampling Spinning |
| VAWI | Variable Wavelength Interferometry |
| VAZC | Vibrationally Adiabatic Zero Curvature (quantum Calcn. Approxn.) |
| VB | Valence Bond |
| VBCI | Valence Bond Configuration Interaction |
| VBHL | Valence Bond Heitler-London (wave Function) |
| VBM | Valence-band Model (in Electronic Structure Calcns.) |
| VBR | Variational Basis Representation (in Quantum Calcns.) |
| VBS | Virtual Bound State Model |
| VBSCF | Valence Bond Self-consistent Field |
| VBXES | Valence Band X-ray Emission Spectroscopy |
| VBXPS | Valence Bond X-ray Photoelectron Spectroscopy |
| VC | Vapor Compression |
| VC | Vital Capacity (lung Function) |
| VCA | Virtual Crystal Approximation |
| VCAM-1 | Vascular Cell Adhesion Mol. 1 |
| VCB-CPA | Virtual Crystal Bandwidth-coherent Potential Approxn. (for Electronic-structure Calcns. On Alloys) |
| VCC | Variable Curvature Coordinates (in Calcns. On Mol. Vibrations) |
| VCC-IOS | Vibrational Close-coupling-(rotational) Infinite-order Sudden (for Inelastic Mol. Collisions Calcns.) |
| VCC-RIOS | Vibrational Close-coupled-rotational Infinite Order Sudden |
| VCCPB | Variable-charge Coulomb-projected Born (approxn. For Electron-atom Scattering) |
| VCD | Vapor Compression Distillation |
| VCD | Vibrational Circular Dichroism |
| VCDT | Vienna Canyon Diablo Troilite |
| VCDW | Vector Charge-density Wave |