Critical reviews in solid state and materials sciences
Paginering:
Jaargang 6 (1976) nr. 3 pagina's 239-252
Jaar:
1976-06-01
Inhoud:
The aim of chemisorption theory is to achieve for any adsorbateladsorbent system complete quantum predictions of the equilibrium positions of all the nuclei, the ground-state (electronically adiabatic) potential energy surface, the electronic excitation spectrum, and the response of the system to external probes. We are still a very long way from this goal, but some simplified models can now be explored in depth. Serious quantitative work begins with Toya,1,2 and my review ends with the work of Appelbaum and Hamann3 These works provide examples of two of the three approaches to chemisorption theory. Toya's is a configuration interaction (CI) approach, using the states of the noninteracting adsorbate/solid system as basis states; Appelbaum and Hamann try to integrate Schrodinger's equation directly. The third approach is the linear combination of atomic orbitals molecular orbital (LCAO-MO) theory, and I begin with it because it is generally familiar in its simpler forms through its widespread use in molecular quantum mechanics. However, I remark at this stage that the direct integration of Schrodinger's equation may be more economical in computer time than the traditional quantum chemistry approach; it is certainly more economical if the nonlocal Hartree-Fock exchange potential is replaced by a local approximation to it.
Tijdschrift beschrijving