The method of increments - a wavefunction-based ab inition correlation method for solids
Beate Paulus
Max-Planck-Institut für Physik komplexer Systeme
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An overview of wavefunction-based correlation methods generalised for the application
to solids is presented. Those methods based on a preceding HF treatment explicitly calculate
the many-body wavefunction in contrast to the density-functional theory which relies on the
ground-state density of the system.
The talk focuses on the so-called method of increments where the correlation
energy of the solid is expanded
in terms of localised orbitals or of a group of localised orbitals.
The method of increments is applied to a great variety of materials,
from covalent semiconductors to ionic insulators, from large band-gap materials
like diamond to the half-metal $\alpha$-tin, from large molecules like fullerenes
over polymers, graphite to three-dimensional solids. Rare-gas crystals where the
binding is van der Waals like are treated as well as solid mercury, where the
metallic binding is entirely due to correlation. Strongly correlated
systems are examined and the correlation driven metal-insulator transition is described at an
ab-initio level.