What are the units of the radial wavefunction in my FORTRAN code?

In summary, the conversation discusses the use of FORTRAN and the Euler method to solve for the Hydrogen wavefunction. The solution is then compared to an analytic solution, which is also normalized. There is confusion about the units of the analytic solution and whether or not the units for the wavefunction should be included on graphs. The radial part of the wave function is normalized according to a specific integral.
  • #1
peanutbutter
8
0
I am solving the Hydrogen wavefunction using FORTRAN.
Now using the Euler method, I am given a solution to match which is given by u10(r) = 1.06r*exp(-3.74r) (where unl(r) = rRnl(r) in general) which says it has a normalisation chosen to match what i should get from my code.

Then I use the backwards Euler method getting a more accurate solution with a correct shape and a much larger amplitude. I then normalise this and plot it against the analytic solution given by
u = 1/pi^1/2*(1/ao)^3/2*r*exp(-r/a0) which is apparently also normalised.

I am working in natural units so h-bar = c = 1 and me = 511.7keV the electron mass, which implies that my Bohr radius = 0.26737keV^-1 and I am working in units of r given by keV^-1 also.

so this would imply that the units of u for the analytic solution must be keV^(1/2) however looking at the original equation shouldn't the units be keV^-1 as u = rR(r) where r has units keV^-1 and R(r) is dimensionless, I'm confused. Is my normalisation unit calculated in fortran supposed to have units like the analytic normalisation constant?

On my graphs should I just put no units? :S
Any suggestions would be appreciated, units of wavefunctions has always confused me.
 
Last edited:
Physics news on Phys.org
  • #2
The radial part of the wave function is normalized according to
$$
\int_0^\infty R_{nl}(r) r^2 \, dr = 1
$$
which means that ##R_{nl}## has the same units as ##r^{-3}##.
 

What are units of radial wavefunction?

The units of radial wavefunction depend on the specific system being studied. In general, they have units of length^-1 or volume^-1. For example, in the case of an electron in an atom, the units of radial wavefunction would be angstrom^-3.

How is the radial wavefunction related to the probability density?

The radial wavefunction squared is proportional to the probability density of finding a particle at a certain distance from the nucleus. This means that the maximum value of the radial wavefunction occurs at the most probable distance from the nucleus.

What is the significance of the nodes in the radial wavefunction?

Nodes in the radial wavefunction represent regions where the probability of finding a particle is zero. They are important in understanding the spatial distribution of the electron in an atom and can help determine the energy state of the system.

How are the units of radial wavefunction related to the principal quantum number?

The units of radial wavefunction are related to the principal quantum number (n) as they increase with increasing n. This is because the radial wavefunction represents the probability of finding an electron at a certain distance from the nucleus, and as n increases, the probability of finding an electron at larger distances increases as well.

Can the radial wavefunction be used to determine the energy of a system?

Yes, the radial wavefunction is a crucial part of the Schrödinger equation, which is used to calculate the energy levels of a system. The radial wavefunction, along with the angular wavefunction and the quantum numbers, helps determine the overall wavefunction of the system, which is then used to calculate the energy.

Similar threads

  • Quantum Physics
Replies
5
Views
832
  • Quantum Physics
Replies
11
Views
7K
Replies
10
Views
2K
  • Advanced Physics Homework Help
Replies
1
Views
3K
  • Introductory Physics Homework Help
Replies
2
Views
3K
Replies
8
Views
1K
  • Quantum Physics
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
12
Views
733
  • Calculus and Beyond Homework Help
Replies
6
Views
391
  • Linear and Abstract Algebra
Replies
2
Views
967
Back
Top