Structural, dynamic, and spectroscopic properties of self-consistent charge density functional tight binding water models

Doctoral Dissertation
Thumbnail

Abstract

Because of its importance as a solvent and its many unique properties, water is a widely studied substance. Computational modeling can bring insight to detailed mechanisms of the interactions of water with itself or other chemicals. The accuracy of simulations of aqueous systems are limited by the accuracy of the water model used. A wide range of empirical models which accurately reproduce bulk water have been developed, but are limited to nonreactive systems. Ab initio models can accurately reproduce water properties, including reactions, but are limited to small systems. Semiempirical models can access larger systems and include reactions, but the transferability of the models is limited by the parameterization. The self-consistent charge density functional tight binding (SCC-DFTB) model was developed in the 1990s to have greater transferability and reliance on fewer parameters. The DFTB+ implementation of SCC-DFTB allows for second- and third-order expansions of the density fluctuations in the energy. For each of these models the structural, dynamic, and spectroscopic properties of bulk SCC-DFTB water are compared to an empirical model, SPC/E, and experimental properties. Although all of the SCC-DFTB models exhibit some failures characteristic of the parent density functional theory, the third-order models are the best models. The experimental-density third-order model best reproduces the liquid structure and rotational dynamics, while the ambient-density third-order model best reproduces the diffusion and infrared line shape.

Attributes

Attribute NameValues
URN
  • etd-11172011-093338

Author Laura Kinnaman
Advisor J. Daniel Gezelter
Contributor Jacek Furdyna, Committee Member
Contributor Jonathan Sapirstein, Committee Member
Contributor J. Daniel Gezelter, Committee Member
Degree Level Doctoral Dissertation
Degree Discipline Physics
Degree Name PhD
Defense Date
  • 2011-10-14

Submission Date 2011-11-17
Country
  • United States of America

Subject
  • diffusion

  • infrared spectroscopy

  • time correlation

  • hydrogen bonding

  • radial distribution function

Publisher
  • University of Notre Dame

Language
  • English

Record Visibility and Access Public
Content License
  • All rights reserved

Departments and Units

Files

Please Note: You may encounter a delay before a download begins. Large or infrequently accessed files can take several minutes to retrieve from our archival storage system.