Density Matrix Approach to Atomic Structure of Solid State Electronic Devices and Rocket Propellants

摘要

The report is a brief survey of density matrix methods developed and applied in the investigation of the electronic structure of atoms. Accurate atomic wavefunctions have been generated, and then analyzed using density matrix techniques. A comparison of ground and excited state wavefunctions showed the changes in the density matrices which occur on excitation. Atomic density matrices were partitioned into an uncorrelated reference state and a correlation in order to study correlation effects. The Hyper-Hartree-Fock scheme was subjected to a density matrix analysis to show the problems which can arise when a state is not N-representable. A decomposition of the energy of an atom into geminal contributions, and a comparison of the Coulomb and Fermi correlation effects was made. A perturbation expansion of the natural orbitals of two-electron atoms in inverse powers of the nuclear charge was made with the hope of providing information which can be used in building inner shells of larger atoms. (Author)