How Do Units Affect Hydrogen Wavefunction Normalization in FORTRAN?

Click For Summary
SUMMARY

The discussion focuses on the normalization of the Hydrogen wavefunction in FORTRAN, specifically using the Euler and backward Euler methods. The user compares their numerical solution, u10(r) = 1.06r*exp(-3.74r), with the analytic solution u = 1/pi^1/2*(1/ao)^3/2*r*exp(-r/a0). The user operates in natural units where h-bar = c = 1 and the electron mass is set to 511.7 keV. The confusion arises regarding the units of the wavefunction, particularly whether the normalization constant should align with the analytic solution's units of keV^(1/2) or keV^-1.

PREREQUISITES
  • FORTRAN programming for numerical methods
  • Understanding of wavefunction normalization in quantum mechanics
  • Familiarity with natural units in physics
  • Knowledge of the Euler and backward Euler methods
NEXT STEPS
  • Study the normalization condition for wavefunctions in quantum mechanics
  • Learn about the implementation of the backward Euler method in FORTRAN
  • Research the implications of using natural units in quantum physics
  • Explore the mathematical derivation of the Hydrogen wavefunction
USEFUL FOR

Physicists, computational scientists, and students working on quantum mechanics simulations, particularly those using FORTRAN for numerical solutions of wavefunctions.

peanutbutter
Messages
7
Reaction score
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.
 
Physics news on Phys.org
Wavefunction units can be tricky, but you can get it from the normalization condition:
∫ Ψ*Ψ dx dy dz = 1​
Since the "1" is dimensionless, and "dx dy dz" is a volume, the wavefunction must have units of volume-1/2 or length-3/2
 

Similar threads

  • · Replies 18 ·
Replies
18
Views
2K
Replies
26
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 11 ·
Replies
11
Views
8K
  • · Replies 2 ·
Replies
2
Views
10K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
14K