Accession Number:

ADA569242

Title:

Dielectric Response at THz Frequencies of Mg Water Complexes Interacting with O3 Calculated by Density Functional Theory

Descriptive Note:

Memorandum rept. 1 Oct 2011-1 Aug 2012

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC CENTER FOR COMPUTATIONAL MATERIALS SCIENCE

Report Date:

2012-10-24

Pagination or Media Count:

67.0

Abstract:

The need for better monitoring of water quality and levels of water contamination implies a need for determining the dielectric response properties of water contaminants with respect to electromagnetic wave excitation. In addition to monitoring contaminants, there is an associated need for monitoring chemical processes whose purpose is deactivation or assistance in the removal of water contaminants. Two naturally occurring water contaminants, which are the result of decaying vegetation, are Iron and Manganese, where Iron is in general at much higher concentrations. Correspondingly, a process that is highly effective for assisting filtration of water contaminants, including Iron and Manganese, is the addition in solution of Ozone, i.e., the preozonation process. The present study is based on significant progress in density functional theory DFT, and associated software technology, which is sufficiently mature for the determination of dielectric response functions, and actually provides complementary information to that obtained from experiment. This point is further demonstrated in this study by calculations of ground state resonance structure associated with water complexes of Mg and the interaction of these complexes with Ozone using DFT. The calculation of ground state resonance structure is for the construction of parameterized dielectric response functions for excitation by electromagnetic waves at frequencies within the THz range. The THz range is associated with ground state resonance structure, in contrast to frequencies that can induce appreciable electronic state transitions. Dielectric functions provide for different types of analyses concerning the dielectric response of water contaminants. In particular, these dielectric response functions provide quantitative initial estimates of spectral response features for subsequent adjustment with respect to additional information such as laboratory measurements and other types of theory-based calculations.

Subject Categories:

  • Physical Chemistry
  • Water Pollution and Control

Distribution Statement:

APPROVED FOR PUBLIC RELEASE