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Lecture note 26.08.2015 - Hydrogen Wavefunctions

In this lecture we have looked at the well known hydrogen wavefunctions (and spectra) using several tools.
Links are given below.
Matlab scripts are available - some are linked to, some will be made available later (they need editing)
The radial functions and spherical harmonics are in  hydro_YLM/index.html  and
the last part of this page is also in   visual_N_5_L_2/index.html  (for a simpler look)

Most of the basic topics which we might need are covered for example in these  LINKS:  
      Hydrogen atom wavefunctions http://en.wikipedia.org/wiki/Hydrogen_atom#Wavefunction
      Laplace operator     http://en.wikipedia.org/wiki/Laplace_operator#Three_dimensions
      Legendre Polynomials  http://en.wikipedia.org/wiki/Legendre_polynomials
      Spherical harmonics  http://en.wikipedia.org/wiki/Spherical_harmonics
                   Table of them http://en.wikipedia.org/wiki/Table_of_spherical_harmonics

                  List of Radial functions: http://en.citizendium.org/wiki/hydrogen-like_atom#List_of_radial_functions
see also the whole article  http://en.citizendium.org/wiki/hydrogen-like_atom - better than wikipedia

Atomic data on the web
National Institute of Standards and Technology  (NIST) atomic data databases        http://www.nist.gov/
See also https://en.wikipedia.org/wiki/National_Institute_of_Standards_and_Technology
Spectrum of hydrogen from states up to L=40 - details remain hidden due to resolution
This is a Java Applet at http://physics.nist.gov/PhysRefData/ASD/lines_form.html     -  The Grotrian Diagram (Java)
                                             / unfortunately, Java Applets might soon be forbidden in all browsers   -  keep one old for your studies ... /
see also last year's   2014_08_26/index.html
      zNIST_hydrogen_2015.png

       zNIST_hydrogen_2015.png

Schrödinger equation for hydrogen atom
Spherical coordinates; Laplace operator in spherical coordinates
Kinetic energy - separates to radial motion and the angular momentum squared term - just as in classical physics
for RADIAL POTENTIALS  - or as we say spherically symmetric potentials - potential depends only on distance r
Operator denoted Lambda squared
      xcf_1000.png

       xcf_1000.png

Separation of variables  -  very often used trick  -
A partial-differential equation is "separated" to several (two) equations in subsets of variables
            --    if the differential operator (must be LINEAR) can be written as sum of terms depending each on one of the subsets
Here we show this for a case of totally TWO variables, the total diff. op. L can be written as a sum of  L_ksi   and L_eta

Then some solutions can be found as PRODUCT of two functions.
Assuming one such solution, we find that the equation separates into two equations - because of each term is seen to be a constant

A general solution can then be a sum of various such product solutions  -  due to the LINEARITY of the original differential (partial) operator.
      xcf_1010.png

       xcf_1010.png

In case of the hydrogen atoms we obtain the separation into a radial equation - to be solved
And the equation for so called SPHERICAL Harmonics

The type of spherical harmonics used in atomic physics might differ from spherical harmonics used in other fields
(e.g. chemistry - there are often used the "real spherical harmonics" - linear combinations of those used here )
      xcf_1020.png

       xcf_1020.png

Spherical harmonics  --  a field of mathematics known e.g. as SPECIAL FUNCTIONS
...    Orthogonal polynomials; orthogonality of functions; expansion in sets of functions ..... etc
      xcf_1030.png

       xcf_1030.png

Visualization of spherical harmonics by polar plot in theta and phi 
  hydro_YLM/index.html  this contains both the the polar plots of  Spherical Harmonics and the plotting of Radial Functions and densities.
Polar plot  - theta from 0 (up) to pi (down) - phi goes the 360 degrees - 2 pi.   Just like the geographic system, but there theta goes from -90 to 90.
(and the mathematics would be slightly uglier for our integrations)
      xcf_1040.png

       xcf_1040.png

Radial solutions list from CITIZENDUM   
List of Radial functions: http://en.citizendium.org/wiki/hydrogen-like_atom#List_of_radial_functions
( see also the whole article  http://en.citizendium.org/wiki/hydrogen-like_atom - better than that on wikipedia)
      z-Psi_hydrogen_citizendum.png

       z-Psi_hydrogen_citizendum.png

Visualization of hydrogenic wavefunctions

There are many examples - usually one shows the spherical harmonics, and the radial functions
We have seen at those, but below are also visualizations of total "probability density" 
A systematic comparison is given at the end
Spherical harmonics table - L and its maximum M=L       and   several M=0 for various L values 
See the details in hydro_YLM/index.html     
                                                                                                                  z_0012_Matlab-Doughnut_M-equal_L-rotation.png

     z_0012_Matlab-Doughnut_M-equal_L-rotation.png

----
      zPsi_7_3_2.png

       zPsi_7_3_2.png

Zoomed      N=7  L=5  M=3 
      zPsi_7_5_3_newcol.png

       zPsi_7_5_3_newcol.png

Standard picture from our Matlab script   N=5   L=3  M=2
      zPsi_5_3_2.png

       zPsi_5_3_2.png


Below is a systematic comparison of all the features for              n=5   l=2  m=0, 1, 2


Visualization of hydrogenic wavefunctions                 Hydrogenic states  n=5   l=2  m=0, 1, 2         ( Matlab scripts available )

          Computer Algebra in Matlab  - the radial function  ( so called pretty-print in 1980-style )

Radial function   n=5   l=2              and     the Radial density

                        


Spherical Harmonics   l=2        m=0       m=1       m=2

                   

Spherical harmonics
polar plot, absolute values squared



The wavefunctions
      product of radial and Spherical harmonics

absolute value squared, each dark color doubling
cut through the x-z plane


The wavefunctions
      product of radial and Spherical harmonics

Three function values isosurfaces
0.1         2           8        


               



                    


      









  








   

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