Spherical harmonics and wavefunctions

In summary: But the radial part is just a mathematical construct, and has no real world physical significance.It's just a drawing of the surface of maximum probability density, which is the same for 2p and 2p spherical harmonic.Multiplying the radial wave function by constant factor changes the size, not the shape, of the "drawing" of the orbital, which is really just a drawing of the surface of maximum probability density.
  • #1
Chemist20
86
0
What's the difference in the representation of spherical harmonics and the orbitals themselves? they look exactly the same to me... unlike the radial part of the wavefunction though.
 
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  • #2
The angular part of an orbital wave function for hydrogen (or any other spherically symmetric potential) is a spherical harmonic:

[tex]\Psi_{nlm}(r,\theta,\phi) = R_{nl}(r)Y_{lm}(\theta,\phi)[/tex]
 
  • #3
jtbell said:
The angular part of an orbital wave function for hydrogen (or any other spherically symmetric potential) is a spherical harmonic:

[tex]\Psi_{nlm}(r,\theta,\phi) = R_{nl}(r)Y_{lm}(\theta,\phi)[/tex]

yes but for a 2p for example, what's the difference in representation between the orbital itself and the spherical harmonic? they look the same to me.
 
  • #4
Chemist20 said:
yes but for a 2p for example, what's the difference in representation between the orbital itself and the spherical harmonic? they look the same to me.
The angular parts look the same, because they are identical (see jtbell's comment). Unlike spherical harmonics, orbital wave functions, however, do not consist only of an angular part. They also have a radial part. And this radial part is non-trival and comes from solving the Schroedinger equation for some potential (e.g., in hydrogen the nuclear attraction of the proton, in higher spherical atoms from nuclear attraction and the mean field of the other electrons (Fock potential)). But this has no influence on the angular part. E.g., 2p and 3p orbitals have the same angular part, not only in a single atom, but across all atoms (in the nonrelativistic case etc.).
 
  • #5
cgk said:
The angular parts look the same, because they are identical (see jtbell's comment). Unlike spherical harmonics, orbital wave functions, however, do not consist only of an angular part. They also have a radial part. And this radial part is non-trival and comes from solving the Schroedinger equation for some potential (e.g., in hydrogen the nuclear attraction of the proton, in higher spherical atoms from nuclear attraction and the mean field of the other electrons (Fock potential)). But this has no influence on the angular part. E.g., 2p and 3p orbitals have the same angular part, not only in a single atom, but across all atoms (in the nonrelativistic case etc.).

yes, but when drawing the 2p orbital and the 2p spherical harmonic what's the difference? THEY ARE THE SAME!
 
  • #6
If they are the same, then by the property of sharing the same identity they are not different.
 
  • #7
Chemist20 said:
yes, but when drawing the 2p orbital and the 2p spherical harmonic what's the difference? THEY ARE THE SAME!
Note that multiplying the radial wave function by constant factor changes the size, not the shape, of the "drawing" of the orbital, which is really just a drawing of the surface of maximum probability density. By looking at how more general changes in the radial wave function affects this surface, you can see why spherical harmonics look so much like these surfaces.
 

1. What are spherical harmonics and wavefunctions?

Spherical harmonics are mathematical functions that describe the spatial distribution of a wave in three dimensions. They are used to represent the angular component of wavefunctions in quantum mechanics. Wavefunctions, on the other hand, are complex-valued functions that describe the quantum state of a physical system.

2. What is the significance of spherical harmonics and wavefunctions?

Spherical harmonics and wavefunctions are crucial in understanding the behavior of particles at the quantum level. They are used to solve the Schrödinger equation, which is the fundamental equation in quantum mechanics. They also provide insight into the energy levels and properties of atoms, molecules, and other quantum systems.

3. How are spherical harmonics and wavefunctions related?

Spherical harmonics are a type of wavefunction that describes the angular component of a wave. They are used in conjunction with other types of wavefunctions, such as radial wavefunctions, to fully describe the quantum state of a system. The product of the two types of wavefunctions gives the overall wavefunction for a system.

4. What are the physical interpretations of spherical harmonics and wavefunctions?

The physical interpretations of spherical harmonics and wavefunctions vary depending on the context. In general, they represent the probability amplitude of finding a particle in a specific energy state and location. Spherical harmonics, specifically, describe the shape of electron orbitals in an atom.

5. How are spherical harmonics and wavefunctions used in practical applications?

Spherical harmonics and wavefunctions are used extensively in a wide range of fields, including physics, chemistry, and engineering. In physics, they are used to model atomic and molecular systems, while in engineering they are used to analyze and design antennas and other wave-based technologies. Additionally, they are also used in computer graphics and image processing to represent and manipulate 3D data.

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