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 |
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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 |
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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