Approximation Methods in Quantum Mechanics- Semester 2 M.Sc 2021-23 copy 1
Unit 2 : Approximation Methods in Quantum Mechanics (18 Hrs)
2.1 Many-body problem and the need of approximation methods, independent particlemodel. Variation method:Variation theorem with proof, illustration of variation theorem using the trial function x(a-x) for particle in a 1D-box and using the trial function e-αr for the hydrogen atom, variation treatment for the ground state ofhelium atom.
2.2 Perturbation method, time-independent perturbation method (non-degenerate case only), first order correction to energy and wave function, illustration by application to particle in a 1D-box with slanted bottom, perturbation treatment of the ground state of the helium atom. Qualitative idea of Hellmann-Feynman theorem.
2.3 Hartree-Fock method,multi-electron atoms. Hartree-Fock equations (no derivation).
The Fock operator, core hamiltonian, coulomb operator and exchange
operator.Qualitative treatment of Hartree-Fock Self-Consistent Field (HFSCF)
method. Roothan's concept of basis functions, Slater type orbitals (STO) and Gaussian
type orbitals (GTO), sketches of STO and GTO.
Approximation Methods in Quantum Mechanics- Semester 2 M.Sc 2021-23
Unit 2 : Approximation Methods in Quantum Mechanics (18 Hrs)
2.1 Many-body problem and the need of approximation methods, independent particlemodel. Variation method:Variation theorem with proof, illustration of variation theorem using the trial function x(a-x) for particle in a 1D-box and using the trial function e-αr for the hydrogen atom, variation treatment for the ground state ofhelium atom.
2.2 Perturbation method, time-independent perturbation method (non-degenerate case only), first order correction to energy and wave function, illustration by application to particle in a 1D-box with slanted bottom, perturbation treatment of the ground state of the helium atom. Qualitative idea of Hellmann-Feynman theorem.
2.3 Hartree-Fock method,multi-electron atoms. Hartree-Fock equations (no derivation).
The Fock operator, core hamiltonian, coulomb operator and exchange
operator.Qualitative treatment of Hartree-Fock Self-Consistent Field (HFSCF)
method. Roothan's concept of basis functions, Slater type orbitals (STO) and Gaussian
type orbitals (GTO), sketches of STO and GTO.