Cluster Studies of Chemisorption Using Total Energy Techniques.
Abstract
Available from UMI in association with The British Library. Requires signed TDF. Chapter 1 introduces the topic. Chapter 2 contains a discussion of ab initio quantum chemistry techniques and in particular the self consistent Hartree-Fock equations. Section 2.2 discusses the Hartree -Fock equations and their matrix form the Roothaan-Hall equations. Section 2.3 deals with the important question of the choice of a basis set for molecular calculations and in section 2.4 we move on to present a brief review of the GAMESS SCF MO package. Finally, section 2.5 deals with methods of moving beyond HF theory by including electron -electron correlation effects. Chapters 3, 4 and 5 deal with applications of the ab initio method to real systems. Chapter 3 details calculations performed on the formate and methoxy radicals on the Cu(100) surface, while chapter 4 looks at the controversial topic of the low temperature structure of oxygen on Cu(110). Finally, chapter 5 considers the effects of atomic oxygen chemisorption on the Si(100)(2 times 1) reconstructed surface. While the preceding three chapters highlight the virtues of ab initio methods, chapter 6 points out some of their vices and in particular the severe demands they make on computational resources. Alternative semi-empirical techniques are then introduced in the form of the extended Huckel and ASED methods. In particular, we discuss the role of charge self consistency in semi-empirical techniques and show that in contrast to other methods, it has little effect on the quality of results produced using the ASED method. Finally, we conclude in chapter 7 by reviewing the thesis and suggesting possible future developments to this work, both in terms of interesting systems to investigate and new directions in which the theory could be developed. (Abstract shortened with permission of author.).
- Publication:
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Ph.D. Thesis
- Pub Date:
- 1989
- Bibcode:
- 1989PhDT.......168W
- Keywords:
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- Physics: Condensed Matter