| UA |
united atom |
| UAMO |
unprojected alternant molecular
orbital |
| UBA |
unitarized Born approxn. |
| UBFF |
Urey-Bradley force field
- E.B. Wilson Jnr, J.C. Decius, and P.C. Cross, Molecular Vibrations.
The theory of infrared and raman vibrational spectra (McGraw Hill,
New York, 1955 (reprinted in 1980 by Dover Books)), p. 179 |
| UCAS-SCF |
unrestricted complete active
space self-consistent field |
| UCC |
unitary coupled-cluster |
| UCC(n) |
unitary coupled-cluster
[truncated to nth order] |
| UCCD |
(spin)unrestricted coupled
cluster (with) double (excitations) |
| UCDW |
ultrarelativistic continuum
distorted wave |
| UCEPA |
unitary coupled electron
pair approximation |
| UCHF |
uncoupled Hartree-Fock |
| UCHFPT |
uncoupled Hartree-Fock
perturbation theory |
| UCID |
unrestricted ci (with)
single (and) double (excitations) |
| UDF |
unrestricted Dirac-Fock |
| UDWA |
unitarized distorted-wave
approximation |
| UDWBA |
unitarized disorted wave
Born approxn. (for scattering) |
| UEBS |
unitarized Eikonal Born
series (in electron-atom scattering) |
| UEFF |
effective potential (method
for calculating association-reaction rates) - N. Markovic and S. Nordholm,
Chem. Phys., 135, 109 (1989) |
| UGA |
unitary-group approach
(in quantum calcns.) |
| UGF |
unitary-group formulation
(in many-body quantum theory) |
| UHF |
unrestricted open-shell
Hartree-Fock method - A. Szabo & N. S. Ostlund, Modern Quantum
Chemistry (Macmillan, New York, 1982) |
| UHF-AA |
unrestricted Hartree-Fock
(with spin) annihilation |
| UHF-CO |
unrestricted Hartree-Fock
crystal orbital |
| UHFQ |
unrestricted Hartree-Fock
with quartet annihilation |
| UHFS |
unrestricted Hartree-Fock-Slater |
| UHV |
ultrahigh vacuum. |
| UKB |
unrestricted kinetic balance
(in calcns. of wave functions and energies) |
| ULFM |
unified ligand field model
(for mol. electronic energies) |
| UMBPT(n) |
unrestricted many-body
perturbation theory of order n |
| UMINDO |
spin-unrestricted modified
intermediate neglect of differential overlap |
| UMNDO |
spin-unrestricted modified
neglect of diatomic overlap |
| UMO |
unmodified molecular orbital |
| UMP |
unrestricted M�ller-Plesset |
| UMP2 |
unrestricted M�ller-Plesset
2nd-order (perturbation theory) |
| UMP4SDTQ |
unrestricted M�ller-Plesset
4th-order (perturbation theory with) single, double, triple, and quadruple
(excitations) |
| UNIMOL |
the name given to several
(and separate) computer programs for calculating unimolecular rate
coefficients |
| UNO |
unrestricted natural orbital |
| UNO-CAS |
unrestricted natural orbital-complete
active space |
| UOVMO |
unoccupied valence-type
mol. orbital |
| UPA |
unitary-pole approximation |
| UPS |
ultraviolet photoelectron
spectroscopy. |
| UQ-NG |
uniform-quality (basis
set) constructed with a number (n) of gaussian (g) functions |
| UQCISD |
unrestricted quadratic
CI (with) single (and) double (excitations) |
| US |
unified statistical |
| USPC |
unoccupied-states potential
correction |
| UTAO |
undistorted traveling atomic
orbital |
| UW-PG |
uniformly weighted planar
grid (method in calcns. of electron-momentum distributions) |
