Atomic orbital

A less formal description of electrons in atoms can be found at Electron configuration.

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In quantum mechanics, the states of an atom, i.e. the eigenstates of the atomic Hamiltonian, are expanded (see configuration interaction expansion and basis (linear algebra)) into linear combinations of anti-symmetrized products (Slater determinants) of one-electron functions. The spatial components of these one-electron functions are called atomic orbitals. (When one considers also their spin component, one speaks of atomic spin orbitals.)

Related Topics:
Quantum mechanics - Eigenstate - Hamiltonian - Configuration interaction - Basis (linear algebra) - Linear combination - Slater determinant - Electron - Spin

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In atomic physics, the atomic spectral lines correspond to transitions (quantum leaps) between quantum states of an atom. These states are labelled by a set of quantum numbers summarized in the term symbol and usually associated to particular electron configurations, i.e. by occupations schemes of atomic orbitals (e.g. 1s^2 2s^2 2p^6 for the ground state of Neon -- term symbol: {}^1S_0). This notation means that the corresponding Slater determinants have a clear higher weight in the configuration interaction expansion. The atomic orbital concept is therefore a key concept for visualizing the excitation process associated to a given transition. One can say for example for a given transition that it corresponds to the excitation of an electron from an occupied orbital to a given unoccupied orbital. Nevertheless one has to keep in mind that electrons are fermions ruled by Pauli exclusion principle and cannot be distinguished from the other electrons in the atom. Moreover, it sometimes happens that the configuration interaction expansion converges very slowly and that one cannot speak about simple one-determinantal wave function at all. This is the case when electron correlation is large.

Related Topics:
Atomic physics - Atomic spectral line - Quantum leap - Quantum state - Atom - Quantum number - Term symbol - Electron configuration - Neon - Slater determinant - Configuration interaction - Fermion - Pauli exclusion principle - Electron correlation

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