Wavefunction DFT (Mathematica)

In summary, the individual is seeking assistance with using the DFT function in Mathematica to compute wavefunctions. The DFT output is not matching the expected output from the analytical FT, and adjusting parameters such as steps and domain does not solve the issue. The individual is open to any solution that can help them get the correct output. They also mention that sometimes Mathematica may provide a more elegant expression as a result, but the steps to get to that result may yield a different answer.
  • #1
algorhythmic
1
0
This question is not directly related to QM although my reason for asking it is I'm trying to compute wavefunctions on my PC -- please excuse me if this is the wrong place to ask. I am having trouble using the DFT in Mathematica although I don't think my problem is directly Mathematica related.

My problem is that the DFT is not giving me the output I expect, i.e. the output that I get if I take the analytical FT.

In the following images I have the wavefunction as given and compute the CFT and DFT:

CFT : http://imgur.com/WxMTl,ROzWg#1
DFT : http://imgur.com/WxMTl,ROzWg#0

As you can see the although the DFT is correctly normalized to 1, it is incorrectly scaled. If I change the parameters n1 (steps) or L (domain) then this scaling is affected.
I need to do something to get the Fourier[] DFT function to know about the value dx. I have tried adjusting the FourierParemeters option for Fourier and have spent a great amount of time without finding a solution to what seems to be a very simple problem.

Any help would be *greatly* appreciated.

Thanks.
 
Last edited:
Physics news on Phys.org
  • #2
What sort of answer are you looking for, and what do you think that the solution should be? In other words, are you certain that Mathematica is right but that you might be looking at it in a different light. I find this happens a lot with Mathematica; often, I will use it (or Wolfram Alpha) and when I solve an entire solution I will get the more elegant expression as a result (the kind that I would not compute by hand), then I do the steps (in Mathematica) and get a "different" answer (that I would get if I did on paper) and its equivalent.
 

1. What is Wavefunction DFT in Mathematica?

Wavefunction DFT (Density Functional Theory) is a computational method used in the field of quantum chemistry to calculate the electronic structure of molecules and materials. It is implemented in the Mathematica software using the WavefunctionDFT package.

2. How does Wavefunction DFT work?

Wavefunction DFT calculates the electronic structure by solving the Schrödinger equation using a density functional approximation. This involves determining the electron density of the system and using it to calculate the total energy. The calculations are performed using the Kohn-Sham equations and various numerical methods.

3. What are the advantages of using Wavefunction DFT in Mathematica?

One advantage of using Wavefunction DFT in Mathematica is its user-friendly interface. It allows for easy input and visualization of molecular structures and electronic properties. Additionally, Mathematica's powerful computational capabilities make it a versatile tool for studying a wide range of systems and properties.

4. What types of systems can be studied using Wavefunction DFT in Mathematica?

Wavefunction DFT in Mathematica can be used to study a variety of systems, including molecules, solids, surfaces, and nanoparticles. It can also be used to analyze different electronic properties, such as molecular orbitals, band structures, and charge densities.

5. Are there any limitations to using Wavefunction DFT in Mathematica?

As with any computational method, there are limitations to using Wavefunction DFT in Mathematica. It may not accurately capture certain types of interactions, such as dispersion forces, and may not be suitable for studying highly correlated systems. Additionally, the accuracy of the results may depend on the choice of density functional approximation and numerical parameters.

Similar threads

  • Atomic and Condensed Matter
Replies
10
Views
1K
Replies
1
Views
616
  • Quantum Physics
Replies
5
Views
831
Replies
1
Views
790
  • Calculus and Beyond Homework Help
Replies
8
Views
4K
  • STEM Academic Advising
Replies
3
Views
1K
  • Astronomy and Astrophysics
Replies
3
Views
958
  • Quantum Physics
Replies
5
Views
440
  • Atomic and Condensed Matter
Replies
2
Views
2K
Back
Top