Full coupled cluster singles, doubles and triples model for the description of electron correlation (open access)

Full coupled cluster singles, doubles and triples model for the description of electron correlation

Equations for the determination of the cluster coefficients in a full coupled cluster theory involving single, double and triple cluster operators with respect to an independent particle reference, expressible as a single determinant of spin-orbitals, are derived. The resulting wave operator is full, or untruncated, consistant with the choice of cluster operator truncation and the requirements of the connected cluster theorem. A time-independent diagrammatic approach, based on second quantization and the Wick theorem, is employed. Final equations are presented that avoid the construction of rank three intermediary tensors. The model is seen to be a computationally viable, size-extensive, high-level description of electron correlation in small polyatomic molecules.
Date: October 1, 1984
Creator: Hoffmann, Mark Reinhard
System: The UNT Digital Library
Gravel Gertie Confinement Verification Program (open access)

Gravel Gertie Confinement Verification Program

None
Date: March 1, 1984
Creator: Luna, R. E.; Sandoval, R. P.; Taylor, J. M.; Grandjean, N. R.; Keller, L. L. & Newton, G. J.
System: The UNT Digital Library
US uranium mining industry: background information on economics and emissions (open access)

US uranium mining industry: background information on economics and emissions

A review of the US uranium mining industry has revealed a generally depressed industry situation. The 1982 U/sub 3/O/sub 8/ production from both open-pit and underground mines declined to 3800 and 6300 tons respectively with the underground portion representing 46% of total production. US exploration and development has continued downward in 1982. Employment in the mining and milling sectors has dropped 31% and 17% respectively in 1982. Representative forecasts were developed for reactor fuel demand and U/sub 3/O/sub 8/ production for the years 1983 and 1990. Reactor fuel demand is estimated to increase from 15,900 tons to 21,300 tons U/sub 3/O/sub 8/ respectively. U/sub 3/O/sub 8/ production, however, is estimated to decrease from 10,600 tons to 9600 tons respectively. A field examination was conducted of 29 selected underground uranium mines that represent 84% of the 1982 underground production. Data was gathered regarding population, land ownership and private property valuation. An analysis of the increased cost to production resulting from the installation of 20-meter high exhaust borehole vent stacks was conducted. An assessment was made of the current and future /sup 222/Rn emission levels for a group of 27 uranium mines. It is shown that /sup 222/Rn emission rates are increasing …
Date: March 1, 1984
Creator: Bruno, G. A.; Dirks, J. A.; Jackson, P. O. & Young, J. K.
System: The UNT Digital Library