Is DFT Still the Go-To Method for Electronic Structure Calculations?

In summary: The book Density Functional Theory: A Practical Introduction to by Robert Parr and Yang Weitao is recommended. It gives a nice overview of the subject, without going too deeply into the theory. Apparently Density-Functional Theory of Atoms and Molecules (International Series of Monographs on Chemistry) by Robert Parr and Yang Weitao is recommended.
  • #1
Euphemia
12
0
Hi,all
Is there someone's research related to DFT?
I'm an undergraduate trying to get into it.
I hope I could get some help hear if I have any question about that!
Thanks a lot,Euphemia
 
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  • #2
Euphemia said:
Hi,all
Is there someone's research related to DFT?
I'm an undergraduate trying to get into it.
I hope I could get some help hear if I have any question about that!
Thanks a lot,Euphemia
What would one like to know about DFT?

The field has been developing over the last 4 or 5 decades.
 
  • #3
Astronuc said:
What would one like to know about DFT?

The field has been developing over the last 4 or 5 decades.
Ya, you're probably right. But I think the theory still not complete yet!
There are a lot of fine models, and none of them is really based on the first principle.
So I guess there is still something I can do!
 
  • #4
Euphemia said:
Ya, you're probably right. But I think the theory still not complete yet!
There are a lot of fine models, and none of them is really based on the first principle.
So I guess there is still something I can do!
Actually, almost all popular density functionals are either directly derived from first principles (e.g. PBE, TPSS) or based on a mixture of physically meaningful ideas with parameter fitting to accurate reference data (e.g., the LYP correlation functional or the mixing factors in B3LYP).

I don't want to discourage you, but there has been no major breakthrough in (ground state) density functional theory during the last about 10-20 years. These years have seen many very good ideas (most of them based on first principles) which turned out to not actually work any better than PBE or the B3LYP thing. Recent research has actually mostly focused on patching up holes in DFT, like the dispersion problem, but this is not necessarily done in a terribly elegant way; the main goal is typically to get something which more or less works in practice in 90% of the cases. Progress in fundamental problems like a systematic improvability of functionals or the static correlation problem has been very slow. And there are some reasons to believe that obtaining significant further advances in these areas in the context of pure density functional theory is likely impossible.
Many major DFT gurus have actually given up on that and are now making DFTs which are getting closer and closer to wave function methods... (e.g., optimized effective potential methods, random phase approximation correlation, range-separated hybrids, etc.)
 
  • #5
cgk said:
Actually, almost all popular density functionals are either directly derived from first principles (e.g. PBE, TPSS) or based on a mixture of physically meaningful ideas with parameter fitting to accurate reference data (e.g., the LYP correlation functional or the mixing factors in B3LYP).

I don't want to discourage you, but there has been no major breakthrough in (ground state) density functional theory during the last about 10-20 years. These years have seen many very good ideas (most of them based on first principles) which turned out to not actually work any better than PBE or the B3LYP thing. Recent research has actually mostly focused on patching up holes in DFT, like the dispersion problem, but this is not necessarily done in a terribly elegant way; the main goal is typically to get something which more or less works in practice in 90% of the cases. Progress in fundamental problems like a systematic improvability of functionals or the static correlation problem has been very slow. And there are some reasons to believe that obtaining significant further advances in these areas in the context of pure density functional theory is likely impossible.
Many major DFT gurus have actually given up on that and are now making DFTs which are getting closer and closer to wave function methods... (e.g., optimized effective potential methods, random phase approximation correlation, range-separated hybrids, etc.)

That's a fair point.
Thank you for your notification.
I am fascinated by the original idea of DFT, but this theory turns out not really work very well and become very messy. I still want to give it a shot! Since I'm still an undergraduate,
there is no need to be hurry to settle down.
 
  • #6
  • #7
Apparently Density-Functional Theory of Atoms and Molecules (International Series of Monographs on Chemistry) by Robert Parr and Yang Weitao is recommended.
https://www.amazon.com/dp/0195092767/?tag=pfamazon01-20

These might be of interest -

Implementation and Application of Advanced Density Functionals
http://cmt.dur.ac.uk/sjc/thesis_mcg/thesis.html


http://www.ch.ic.ac.uk/harrison/Teaching/DFT_NATO.pdf

http://arxiv.org/abs/physics/9806013

I suspect methods depend on applications, e.g., I believe applications would be different for molecules found in biological systems than those for metals, intermetallics, alloys and ceramics.

I'm becoming more familiar with DFT through some projects at work.
 
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  • #8
Thanks a lot
You are really thoughtful!
 
  • #9
bcbwilla: nice :) i also did research using DFT as an undergrad , but i used DFT methods to generate some trial WF to use on monte carlo methods.
Euphemia: try bcbwilla's suggestion, i found the book at least comprehensible, Density Functional Theory: A Practical Introduction, by scholl.
 
  • #10
Yep, DFT seems to be stucked now, but that also means that you have the chance to make a great breakthrough. It's extremely hard, though. Try it if you really like it!
 
  • #11
I'd like to add that even though density functional theory is more or less stuck at the moment, it still is the most important electronic structure theory out there. Even small progress is important -- this is how things evolve.

Also note that the closely related field of wave function theory, which attempts to achieve basically the same thing as DFT but with a different theoretic approach, is very alive, and has seen immense progress in the recent years. (Wave function methods is what DFT originally replaced in many applications). Contrary to DFT, in those fields wave functions are explicitly constructed from first principles[*], and there are systematic ways to improve the approxmations. If you like first priciples, that might be the right way for you.

[*] (which turns out to be far less impossible than people would make you believe. At this moment it is quite possible to calculate an explicitly correlated coupled cluster wave function with a decent augmented triple-zeta basis set for a 100-atomic molecule.)
 
  • #12
Could someone please send me pages 174 and 175 from YAng Parr density functional theory of atoms and molecules 1989?? I really need them.
 
  • #13
Old thread I know, but I was just at the APS meeting a few weeks ago and it has me thinking about this. There are in fact some methods where you can do some pretty high level wave function stuff on some big systems, which is GREAT. It's not easy though and at least at this point the resources needed aren't readily available to all scientists. For most calculations of most large and relevant systems, DFT is the only game in town.

There are ways of looking at it where DFT is a very elegant theory (solving an alternative problem to the SE) particularly when you see how accurate it can be for a large number of large systems. Of course, a lot of it rests upon fortuitous cancellation of errors and fitting to experimental parameters, which is decidedly in-elegant.

My point is, it seems like everyone is trying to take shots at DFT nowadays, because it's a big and easy target. But, as someone pointed out above, it's the most important electronic structure method of the last thirty years.
 

What is Density Functional Theory (DFT)?

Density Functional Theory (DFT) is a computational method used in quantum mechanics to calculate the electronic structure and properties of materials. It is based on the concept of density, which is a measure of the number of electrons in a given volume.

How does DFT work?

DFT works by solving the Schrödinger equation, which describes the behavior of electrons in a system, using the electron density as the main variable. This allows for a more efficient and accurate calculation of electronic properties compared to traditional quantum mechanical methods.

What are the advantages of using DFT?

One of the main advantages of using DFT is its computational efficiency. It is able to accurately predict electronic properties of materials without the need for large amounts of computing power. DFT also allows for the study of large systems, such as molecules and solids, which would be difficult to study using other methods.

What are the limitations of DFT?

While DFT is a powerful tool, it does have its limitations. One major limitation is the choice of the exchange-correlation functional, which is a mathematical approximation used in the calculations. Different functionals can give different results, so choosing the most appropriate one is important. DFT also does not account for some important physical phenomena, such as dispersion interactions.

What are some applications of DFT?

DFT has a wide range of applications in materials science, including the study of chemical reactions, catalysis, and the electronic and structural properties of materials. It is also used in drug design, environmental studies, and the development of new materials for energy storage and conversion. DFT is constantly being improved and expanded, making it a valuable tool for researchers in various fields.

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