# Questions tagged [density-functional-theory]

For questions about simulations using Density Functional Theory.

102 questions with no upvoted or accepted answers
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• 4,141
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### Calculation of charge transport with the non-orthogonal basis Hamiltonian based on the non-equilibrium Green's function method

I am thinking about one question. If the Hamiltonian matrix is based on the non-orthogonal basis, how to compute the charge conductance with the Non-Equilibrium Green's Function (NEGF) method. Suppose ...
• 193
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### How to do parity analysis of band extrema?

To check whether electronic transitions are allowed between valence band maximum (VBM) and conduction band minimum (CBM) as per Laporte's rule, the parity of VBM/CBM is needed to be known. This paper ...
• 395
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### Scaling and speed-up of real-space DFT calculations using finite elements approach

I have recently encountered this paper in which the authors have formulated Kohn-Sham equations using the finite elements package deal.II, leading to an open-source software called DFT-FE. It stated ...
• 3,921
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### Variation of Conduction band minimum and valence band maximum with applied strain in semconductors

I have been using the Deformation Potential theory to evaluate the electron scattering rates in nanomaterials. In each case, I was under the impression that the Conduction Band Minimum (CBM) and the ...
• 2,603
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### How To make 2D Quantum dots in VESTA

I want to know how to make 2D Quantum dots in Vesta?
• 229
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### Can the electron charge density of two material systems be similar?

Broadly given two electron charge density (ECD) fields, is it possible to distinguish between the elements present in both the systems? Since the ECD does not explicitly present any information on the ...
• 1,481
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### How to calculate anisotropic exchange J $J_{xy}, J_{xz}, J_{yz}, J_{yx}, ...$ using 4-state mapping and DFT?

In this review, the authors present several schemes to calculate various quantities like single-ion anisotropy, DMI, and anisotropic exchange J using DFT. For instance, the DMI term in the y-direction ...
• 2,281
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### VESTA using command line

Can anyone please show me how to make a supercell with VESTA using a single command line without opening a GUI.
• 161
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### SCF calculations for new materials with unknown properties (e.g. charge, spin, magnetization) using Quantum Espresso

Performing SCF calculations for crystal structures using Quantum Espresso sometimes gives me this error. ...
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### d-d transitions in materials with transition metals in DFT

While reading the literature on the absorption spectra of materials from the MPX3 group (M= Mn,Ni,Co, Fe; layered antiferromagnets) I come across expressions such as d-d transitions, which are visible ...
• 601
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• 1,977
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### Constrained geometry optmization: Molecule interacts with its surroundings

I have a water cluster(suppose) generated from MD run. Now, I want to optimize the geometry of only one water molecule of interest using QC methods (e.g. B3LYP/6-31+G(d,p)). I intend that the water ...
• 810
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### How to perform atomistic spin dynamics (ASD) Ab Initio Molecular Dynamics (AIMD) using VASP?

I have tried normal AIMD simulation using VASP for Non magnetic materials. Now, I am interested to perform the molecular dynamics simulations for the finite temperature for Magnetic materials to ...
46 views

### How to read UPF pseudopotential for ultrasoft pseudopotential simple in a fortran program

I'm currently working on calculating semiempirical local and nonlocal matrix elements for Ga. To proceed with my calculations, I need to extract specific parameters from the UPF (Unified ...
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### Discrepancy between Force Convergence in Geometrical Optimization and SCF Calculation in VASP: Reasons and Troubleshooting Suggestions

During a geometrical optimization of ions and lattice parameters in VASP, the forces acting on atoms were minimized to less than 0.01 eV/Å. However, when performing the subsequent self-consistent ...
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### How do I calculate XPS spectra for molecules to match experimental spectra?

I am trying to calculate the XPS spectra using the ICORELEVEL method in VASP, both using initial and final state approaches, for C1s and F1s electrons. My systems are single molecules. However, my ...
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### My INCAR file, POSCAR, and KPOINTS are same for GGA, however after the PBE calculation, I found that the bandgap is Changing. Why is that happened?

INCAR, POSCAR, and KPOINTS are the same but for the same calculation, the bandgap is changing. First, I relaxed the structure then did the self-consistent calculation, and bandstructure calculation. ...
19 views

### How to calculate kslice_b2 and kslice_b1 in wannierization?

How is reduced coordinates calculated in wannier90? examples 17- 18 , 29
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### Are then any material property solvers (from Charge Density) available in python?

I am looking to predict properties like the Bulk Modulus, total energy, etc., all from the charge density I have as input (CHGCAR file)
• 1,481
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### Convex hull calculations with WIEN2k

How does one do the calculation of a convex hull with the WIEN2k code for the formation energy of alloys?
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### Which is better? Rashba effect or Dresselhaus effect?

My current research focus is on the band splitting observed in 2D perovskite. Existing literature suggests that site inversion asymmetry (SIA) may lead to the Rashba effect, while bulk inversion ...
• 405
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### Kslice in brillioun zone

Can anyone help me about the same issue. How to find reduced coordinate of reciprocal lattice vector which defines kslice in brillioun zone?
23 views

### total spin (J-resolved) projected band structure with SOC

I have been asked by a colleague if it is possible to calculate the spin-projected band structure (with SOC) for a material he is studying. He referenced a paper Boschini et al. Sci. Reports 2015 - ...
52 views

### Are the Lagrange multipliers used in Kohn-Sham DFT/HF-based quantum molecular dynamics real valued?

I have seen it written in several places that the matrix of Lagrange multipliers used to impose orthonormality in quantum molecular dynamics schemes based on Kohn-Sham DFT or Hartree-Fock for instance,...
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### Noncollinear band structure calculation with VASP

I am trying to do a band structure calculation of a noncollinear magnetic system. I am getting results that are nowhere close to what I'm expecting. I need help checking if I am following the right ...
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### Electronic Structure Calculation with External Field

There are various programs for calculating energy states for molecules (ORCA, Gaussian, ...). Is there also software that allows the same simulations with an additional external potential (e.g. ...
144 views

### Help with Mathematica for optimizing a Gaussian basis set for a hydrogen atom in a magnetic field

This is a follow-up to my previous question: Optimal Gaussian basis set for hydrogen atom in magnetic field Brief description of the problem I would like to find the ground and excited states of the ...
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