Questions tagged [charge-density]

Questions about charge density.

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5 votes
2 answers
271 views

How to use Multiwfn software (for charge density and ELF analysis)?

I am interested to learn the use of multifwn software. I have windows OS. Mostly I am interested to see the charge density and ELF, particularly in non-atomic locations. Can anyone guide me, starting ...
  • 643
3 votes
0 answers
63 views

Why is my post-processing calculation using Quantum ESPRESSO not complete after 9 hours?

I'm working on an i7 laptop with the parallel version of Quantum ESPRESSO (8 processors are running). I ran a post-processing calculation by ...
  • 707
4 votes
1 answer
185 views

Does integrating PDOS give total charge of a system?

Suppose you have a two atom cubic cell, and you have calculated the atomic PDOS. Does integrating the atomic PDOS and summing them to Fermi energy give exactly the total charge of a system?
  • 643
6 votes
2 answers
296 views

How to calculate the individual atomic charge from a cube file of charge density?

I have a cube file of charge density. The unit cell consists two silicon atoms. If I use a python code to calculate the net charge of the system, it results around 24, which is ok because the ...
  • 643
1 vote
0 answers
33 views

How to perform Bader charge analysis in QUANTUM ESPRESSO?

Suppose I have a test calculation, for two atoms in an unit cell. I have the charge density files in 1D and 3D, calculated using pseudopotential approach. How can I do the Bader analysis with QUANTUM ...
  • 643
2 votes
1 answer
51 views

What is the basic equation for total charge calculation from a 3D cube file of charge density file?

I have a 3D charge density file, calculated from Quantum Espresso DFT. If someone calculates the total charge (number of electrons) of an unit cell from that cube file (using a numerical approximation ...
  • 643
4 votes
1 answer
268 views

Is there any free software that helps to know specific charge densities or ELFs at any position of the material?

Can anyone suggest some free software that can visualize the charge density and/or electron localization function (ELF)? More importantly, can we determine/know those values (charge density and/or ELF)...
  • 643
1 vote
1 answer
68 views

Interstitial charge from a cube file: Need help in python coding

I have a test material- two silicon atoms in an unit cell. This particular structure shows evidence of having interstitial charge between the two atoms. I need to find out the amount of this ...
  • 643
1 vote
0 answers
42 views

Inelastica Pakage

I'm use the Inelastica package to compute MPSH states and analyze the (HOMO/LUMO). For that, I run the Eigenchannels command with : ...
  • 309
6 votes
1 answer
101 views

Total number of electrons from DOS and PDOS - what's the theory behind it?

Let say we need to determine the total number of electrons of an FCC material (let say, two silicon atoms in the unit cell, using numerical/mathematical approach. How can we get the total number of ...
  • 643
5 votes
0 answers
53 views

How to calculate the number of interstital electrons from Quantum Espresso charge density outputs?

I have calculated the charge densities (in 1D, 2D and 3D formats) with the help of Quantum Espresso DFT. The system (/material) is simple, two atoms in an unit cell. However, I want to determine the ...
  • 643
3 votes
0 answers
372 views

PDOS calculation with Quantum Espresso (need help for further analysis)

I have two silicon in an unit cell, for a test calculation. Each silicon as 12 electrons in the pseudopotential (1s is frozen). I have done the partial density of states (PDOS) calculation using DFT ...
  • 643
2 votes
0 answers
32 views

Is there any relation between electride and an electron localization function (ELF)?

I would like to know if there is any correlation between the ELF values with materials in the electronic phase, versus with the electride phase?
  • 643
2 votes
1 answer
242 views

2D charge density contour plot (how to get arbitrary 'Z' values in the plot using python)

I need to generate a contour plot from a file (named abc.gnu) which has X, Y and Z columns of data. It has 1000000 rows of data. I have got the contour plot with a python code (shown at the end). What ...
  • 643
2 votes
0 answers
77 views

|psi|^2 calculation (1D) for diamond structure silicon not showing full dataset for all bands: Quantum ESPRESSO

Dear Quantum ESPRESSO users, I was trying to calculate the |psi|^2 calculation (1D) for diamond structure silicon at a single kpoint (gamma point). I have used the semicore pseudopotential that ...
  • 643
5 votes
0 answers
53 views

"Failed" running DDEC6 Atomic Charge when using Palladium (Pd) cluster model [closed]

I have a problem with running DDEC6 when I used Palladium (Pd) cluster, the main issue was that there were no DDEC6_even_templered_net_atomic_charges.xyz files came ...
  • 51
10 votes
1 answer
739 views

Best software to plot Charge densities

I have obtained cube files of charge density difference using Quantum Espresso. I am trying to plot these as a contour plot in an aesthetically pleasing manner with good quality. I'm aware that ...
  • 731
6 votes
1 answer
247 views

How to extract information from Charge Density Different?

I would like to learn more about Charge density different and would like suggestion for how to get any information from the Charge Density Different plots. How accurate it is and if anyone have ...
16 votes
0 answers
147 views

Calculating the electrostatic potential of a molecule: what is a good 3D Poisson equation solver? [closed]

I was wondering if anybody can recommend an easy-to-use library/program to solve the 3D Poisson equation $\nabla^2 V(r,\theta,\phi) = \rho(r,\theta,\phi)$ with vanishing solutions at infinity: $$V(r,\...
  • 896
7 votes
0 answers
146 views

Why do I get negative charge density values in the core of atoms when I perform DFT calculations with PAW? [closed]

We are all aware of the fact that negative charge densities in the atomic cores are an artefact of Density Functional theory Calculations using Projector Augmented Wave (PAW) method. But what is the ...
  • 1,195
2 votes
0 answers
76 views

How to plot a charge density from a CHGCAR file in Python? [duplicate]

I can convert a CHGCAR file on the NxNxN grid into a 3D array of shape (N,N,N) for better handling, if that helps. At the end of the day, I want plot/visualize the ...
  • 1,195
6 votes
1 answer
459 views

Can a file in the Gaussian CUBE format be voxelized?

My aim is to voxelize a CHGCAR file. I am trying to build up a workflow to do the same. With the aid of the Matter Modeling community members, I have figured out a way to convert a CHGCAR file into ...
  • 1,195
11 votes
0 answers
110 views

Should augmented basis be used for Hirshfeld charges? [closed]

I'm calculating condensed Fukui functions to explain the reactivity of my molecules. The manual for Multiwfn suggests using atomic dipole moment corrected Hirshfeld charges for it. However I get ...
  • 2,333
6 votes
1 answer
107 views

Where are the atoms located in a charge density calculation using DFT?

The charge density (electron distribution) is calculated self-consistently by employing DFT, so a question arises here: where are the atoms located, or are their positions fixed?
  • 1,545
7 votes
1 answer
181 views

How to obtain electron charge density per unit volume about a water molecule using SlowQuant?

@Nike Dattani's answer to How to “get my feet wet” in Density Functional Theory by simulating a water molecule using Python recommends SlowQuant. I've used the install instructions for Linux on my ...
  • 1,994
6 votes
1 answer
120 views

Interpreting Critic2 charge analysis in metallic systems

I'm using Critic2 software to perform post-processing of the charge density of metallic alloys. With the charge density obtained from the Self-Consistent-Field calculation (for that I'm using Quantum ...
11 votes
1 answer
504 views

Charge density convergence within VASP using spin polarized DFT+U

I am noticing a possible convergence problem in a magnetic $U$ system I am studying. In the OSZICAR file I often see the rms(c) value go to about ...
9 votes
1 answer
1k views

What's the difference between charge density and the electron localization function (ELF)?

The following figure is the electron localization function (ELF) for monolayer LaBr$_2$. The ELF is calculated to reflect the bonding character in SL LaBr$_2$. As shown in the figure, ELF shows two ...
  • 14.6k
8 votes
1 answer
178 views

HSE06 Starting Guess

In CASTEP, can you start with a converged density for a lower level of theory for a starting guess for HSE06? If you can, what functional is suggested or is it something that will cause more headache ...
12 votes
1 answer
872 views

What can we learn by inspecting charge densities calculated with DFT?

The charge density is an important physical quantity obtained from first-principles calculations based on density functional theory (DFT). Much useful information about the investigated materials can ...
  • 14.6k
11 votes
2 answers
752 views

Effect of ISYM tag on Partial Density of States (VASP version < 6)

This is from the entry for LORBIT in the VASP Wiki. For LORBIT >= 11 and ...
6 votes
1 answer
104 views

Charge density wave and band inversion

Is there any connection between charge density wave and band inversion? Or is there any system in which band inversion follows the same mechanism as the CDW? I am just trying to find a connection ...
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