32
votes
Accepted
Where is the extended Hückel method (EHM) still used today?
In an era of ab initio methods and many-body methods like the $GW$, there is not too much room for methods like the extended Hückel model to be the main method in any particular field of materials ...
- 4,719
18
votes
State of the art in computational materials design
After a little research I found a great article [1], which provides a good overview to what I asked above in Figure 2. Summarising in a table:
Method
effort
reliability
system size
Interatomic ...
- 2,384
18
votes
Where is the extended Hückel method (EHM) still used today?
One area where the extended-Huckel method continues to see use is to form the initial guess for an SCF calculation or even just a more accurate semi-empirical method. While most electronic structures ...
- 15.2k
14
votes
Where is the extended Hückel method (EHM) still used today?
I know of at least one place, where it is relatively common to use the extended Hückel theory in practise: in generating initial guess orbitals for further electronic structure calculations.
The most ...
- 1,571
11
votes
State of the art in computational materials design
I am sure there are A LOT of authors publishing papers to answer this very question. Mainly because the theories employed have face a paradigm since "one-size-doesn't-fit-all".
Here are the ...
- 1,247
9
votes
Accepted
Is it possible to get complex numbers as solutions for a secular determinant in simple Hückel method (SHM)?
In the Huckel method, you are just generating a very simplified version of the molecular Hamiltonian and determining it's eigenvalues. The molecular Hamiltonian will always be a Hermitian matrix (for ...
- 15.2k
8
votes
Semi-empirical software for bands calculations
DFTB+
One option is DFTB+. It is free, open source, has been around for more than a couple years now, and has a fairly big community.
You are also very lucky, since your question is about the band ...
- 33.6k
8
votes
Accepted
Compute polarizability after each step of relaxed scan in Gaussian 16
This python script will read the logfile from the scan and generate the corresponding gaussian input files.
...
- 2,782
7
votes
Symmetry-preserving low-level structural relaxation
ASE has a FixSymmetry constraint that preserves spacegroup symmetries. It works with a variety of structure optimization algorithms. You could use LAMMPS as the engine or one of the many other ...
- 1,883
5
votes
SCF not converging during RHF/STO-3G geometry optimisation
Based on your input file, I tried to run the calculation in my machine. As you didn't specified how did you obtain the original structure (assembled by hand or downloaded from structure database), I ...
- 4,048
5
votes
SCF not converging during RHF/STO-3G geometry optimisation
If you look at your last five iterations, you will see that the density change (which is what matters most for SCF convergence) is getting smaller in each iteration, meaning that the calculation is ...
- 33.6k
5
votes
Accepted
Symmetry-preserving low-level structural relaxation
GULP
GULP (General Utility Lattice Program) uses specific forcefields for different type of systems and it is designed to work with periodic conditions. Also, it has defined several type of potential ...
- 22.3k
3
votes
Scripts to extract data from MOPAC calculations?
I created the script bellow to extract the data I'm interested in from all MOPAC out files put inside a given folder and create a CSV file with all the data:
...
- 22.3k
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