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Symmetric and unitary group theory and the configuration interaction method

Class at Faculty of Science |
MC260P63

Syllabus

Permutations, their properites and algorithms for their generation mp

Normal mp 1 1 2003-02-07T14:12:00Z 2003-02-07T14:13:00Z 1 gfhghgg 1 1 9.3821 21

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Permutations, their properites and algorithms for their generation

Group of all permutations of normal'>n elements and its properties

Young tableaux, irreducible representations, computation of characters

Young operators, decomposition of the tensor space of orbital products according to irreps

Application in quantum chemistry: construction of spin-adapted antisymmetrized wave functions

The general linear group and their subgroups

Generators of Lie groups and the corresponding Lie algebras

Irreducible representations of the unitary group, Gel'fand basis, connection to the symmetric group

Matrix elements of generators in the Gel'fand basis

Connection to second quantisation, isomorphism between excitation operators and unitary group generators

Formalism for spin ½ particles: Weyl tableaux, Paldus tableaux, hamiltonian matrix elements

Graphical Unitary Group Approach: distinct row table and

Shavitt graph

Practical implementation of the CI method: direct CI, use of point group symmetry

Other CI formulations, contracted CI technique, size-extensivity corrections

General ROHF and CASSCF methods

Introduction to spin adapted coupled clusters method

 

Annotation

This course is intended for advanced undergraduates and Ph.D. students of quantum chemistry, who would like to know more about post-Hartree-Fock methods. We will first deal with basis properties of the symmetric (permutation) group, which has its own application in quantum chemistry and is deeply connected with the unitary group.

Then we will introduce Lie groups and algebras and show application of their theory to the computation of matrix elements of the CI hamiltonian for many electron system.