# Tag Info

## Hot answers tagged charge-density

8

I'm not sure precisely what you mean, but if you want to convert a Cube file to an ($N\times4$) matrix where $N$ is the number of points and the 4 columns are (x,y,z,value), you can try the following code snippet taken from my GitHub repository here, which I reproduce below: cube_filepath = '/path/to/mycube.cube' # Path to Cube File def cube_to_xyzval(...

8

Yes, you can do this. First, do a normal PBE calculation (HSE is built on-top of PBE) which generates an <seed>.check and <seed>.castep_bin file. Then add this line reuse : <name of the check/castep_bin file> to the param file of your HSE06 calculation. This will let CASTEP read in and reuse the previous charge density and wavefunction for ...

8

The typical calculation flow for the density of states is: Geometric relaxation to obtain the lowest-energy structure (CONTCAR) [1relax] (For your system, you should do the spin-polarized calculation by setting ISPIN=2). Using the relaxed structure to perform the electronic self-consistent calculation to obtain converged charge density [2scf]. Using the ...

7

Based on the comments I shared above, it seems that the quality of the charge density is fine. It is just the projection onto atoms that may not be done correctly. If this is indeed the case, then you don't need to re-relax the structure (Step #1). You should be able to read in the charge density and set ISYM=0 (symmetry disabled) and be okay. Disclaimer: ...

6

Firstly regarding the SlowQuant problems: In the version of SlowQuant you are using, the program takes two files as input. The molecules file with the coordinates, number of electrons, and atom IDs. The settings file, see; https://slowquant.readthedocs.io/en/latest/Examples.html. It is in the settings file you would want to add "Charge;Mulliken" ...

6

Judging by your initial energies, it looks like you're starting a calculation from scratch. I've had good luck so far converging spin-polarized calculations by first doing a non-spin-polarized calculation, writing the CHG, CHGCAR, and WAVECAR files, and using those to start a spin-polarized calculation. This is the recommended method if such calculations ...

6

N. Mitsuishi et al. "Switching of band inversion and topological surface states by charge density wave," Nature Communications 11, 2466 (2020) may be of interest to you. I don't think there is any a priori connection between charge density waves and band inversion. Essentially, a charge density wave is a periodic modulation of charge density and ...

5

When you see charge densities plotted in the literature, they are usually plotting particular isosurfaces (contours) and are trying to show "where the electrons are". Charge density differences can be useful in trying to understand the changes in a system, for example charge transfer as a molecule approaches a surface (although this often isn't ...

5

In simple terms, the charge density gives you the probability of finding an electron at a given point, while the electron localization function (ELF) gives you the probability of finding another electron at that same point, therefore it is very sensitive to open shell / shared electron interactions. The ELF equals 0.5 for a metallic-like electron density, ...

2

The atom is divided in three parts: the nuclei, the core electrons and the valence electrons. Each one is treated in a different way. You can do two type of calculation when talking about the system geometry: single-point calculation and geometry optimization. In the case of single-point, the nuclei positions are keep fixed and only the electrons are allowed ...

Only top voted, non community-wiki answers of a minimum length are eligible