Accession Number : ADA466101

Title :   A Multireference Density Functional Approach to the Calculation of the Excited States of Uranium Ions

Descriptive Note : Doctoral thesis

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT

Personal Author(s) : Beck, Eric V

Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a466101.pdf

Report Date : Mar 2007

Pagination or Media Count : 191

Abstract : An accurate and efficient hybrid Density Functional Theory (DFT)/Multireference Configuration Interaction (MRCI) model for computing electronic excitation energies in heavy element atoms and molecules was developed. This model incorporated relativistic effects essential for accurate qualitative and quantitative spectroscopic predictions on heavy elements, while simultaneously removing spin-multiplicity limitations inherent in the original model on which it is based. This model was used to successfully compute ground and low-lying electronic states for atoms in the first two rows of the period table, which were used for calibration. Once calibrated, calculations on carbon monoxide, bromine fluoride, the bromine atom, uranium +4 and +5 ions and the uranyl (UO2 2+) ion showed the model achieved reductions in relative error with respect to Time Dependent Density Functional Theory (TDDFT) of 11-42%, with a corresponding reduction in computational effort in terms of MRCI expansion sizes of a factor of 25-64.

Descriptors :   *IONS , *EXCITATION , *DENSITY FUNCTIONAL THEORY , *URANIUM , TIME DEPENDENCE , THESES , CONFIGURATIONS , COMPUTATIONAL CHEMISTRY , ELECTRON SPECTROSCOPY , CALIBRATION , ELECTRONIC STATES , QUANTUM CHEMISTRY , INTERACTIONS

Subject Categories : Physical Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE