Instructions for computing
exercise on the SCF code herman3
The zip-file of the code and basic instructions are at this address:
https://folk.uib.no/nfylk/PHYS261/2010.10.14/
Following the tasks below, prepare a report.
The report can be discussed during the exam, especially
if you make a nice and thorough study. We shall
also discuss them in the class.
Use the code herman3 as
demonstrated.
On windows, use the command prompt cmd.exe
On Unix/Linux/Mac remember to write
./herman3_MAC < in18
On windows, type only
herman3 < in18
(Comment: there is also herman2, doing nearly the same, only some
details of output files are changed.
It is easier to use herman3, herman2 was adjusted for using plotting in
GNUPLOT )
Task 1
Run the code with available input files inZ (in6, in18 .... in
Calculate several potentials (for several Z).
The name of the potentials and other output-files is taken from the
first line
of the input-line (the existing -
(from Z=2 to Z=28 are available)
Challenge: organizing the output data - you can quickly get too many
ouput
files. Efficient work depends on your organization. For example, copy
the commands you have used, and allways delete all the files you do not
need.
It might be easier to re-compute (using your copied commends) than
keeping
all the output.
Comment on the output files:
the file in13 produced
output files Alum-pot.h-s
Alum310.h-s
Alum300.h-s
Alum210.h-s
Alum200.h-s
Alum100.h-s
together with Alum_gnu.cmd AlumFILE.lst
These last two are not relevant here (gnuplot commands automatically
generated)
The 100 are 1s, 210 are 2p radial functions.
Here we only use the potential files of the type Alum-pot.h-s
This
file contains the pairs r V(r) for about 400 values of r.
At the end there are
also the resulting energies listed. Please,
remove these few last lines,
especially in your spreadsheet or "Origin" work
Optional Task 1a
example: construct in47 using the
configurations given in https://folk.uib.no/AMOS/Hartree/Num.html
The details of the input file are described here: https://folk.uib.no/AMOS/Hartree/inputs.html
hint: modify in28 to in47 adding the configurations
as described in the above link.
Note:
take care of the variables Z,
ncores, nvales, ion
for Aluminium,
they are
13
4
1 0
Z=13, four filled orbitals, one
partially filled orbital, and it is not ionized
https://folk.uib.no/AMOS/Hartree/
https://folk.uib.no/AMOS/Hartree/lindex.html
Gives the overview of all files
Task 2
Find the alpha range parameter for different Z by studying the
potentials output
example: Alum-pot.h-s
Method: for example EXCEL, OpenOffice-CALC or MATLAB
Plotting the potential is not too interesting. Instead, we start by
producing -r*V(r)
- it should go from Z for small
r to 1
for large r
Try to fit this by Z_eff(r)
= (Z-1)*exp(-r/potrange) + 1
How would you do this efficiently?
Describe your method in the report ....
Best procedure:
Divide the data by the model
First step - Z_eff(r) as above,
compared to -r*V(r)
Next step -
divide the data -r*V(r)
by the model for Z_eff(r)
(the result should be always one for best fit - easy to see how good is
the fit)
Compare the potrange values
for the different Z
Task 2a
Model for Z-dependence of potrange
(or alpha in our lecture notes)
Task 3
Using the provided files
in193d and in194s (i.e. in19
for the 19th electron in 3d or in 4s)
convince yourself from the output energies that
indeed, the 4s has lower energy
Copy the output of the two runs into your report and discuss the results
Optional: Show the same situation for the next alcalic metal, including
the filling
of 5s before filling 4d.
For this you must study the Periodic table with configurations
and extend the input files considerably (as in the optional task 1a above)
Optional Task 4
Follow the instructions at https://folk.uib.no/AMOS/Hartree/
and perform a study of radial wavefunctions,
comparing the hydrogen-like with the output in files of the type.
This is best done in MATLAB or OCTAVE, but it can also be done
using a spreadsheet program, like in the tasks above.
This requires also to run the other program for hydrogenic
functions, radhyd3.exe
This asks for parameter 1 (enter 1) and then parameter Z
It produces many data files (listed in the commands)
To compare two functions, you might use e.g.
columns A,B for first series, with C,D empty
and then after that columns C,D for the second function,
with A,B empty. (see the attached two-functions.ods (OpenOffice)
and two-functions.xls (Excel)
(The range of r-values can be too long, just cut away the
uninteresting large r-values.)
Follow the examples in
https://folk.uib.no/AMOS/Hartree/H-S-Prog.html
(click on the pictures to get large ones)
This is about trying to approximate a wavefunction by
a hydrogen-like for effective Z.
(it works for 1s, not for any other orbital, but
it is interesting to try it)
You can also try to explore/compare the two potentials
as in
https://folk.uib.no/AMOS/Hartree/potential.html
The Report
The report should contain at least the results and description
of the work (documented) for tasks Task
1, Task 2 and Task 3
The optional tasks would be interesting
The reports can be in any electronic format. A presentation
might be easiest format to make (with images) (ppt or odp format)
I will come later with the details of how to upload the reports.
Good luck!