Questions tagged [solid-state-physics]
Questions about solid state physics.
92 questions
8 votes
1 answer
152 views
Mapping atomic coordinates between tetragonal and monoclinic crystal structures
In the tetragonal system, the lattice parameter matrix is ([3.003, 0.000, 0.000], [0.000, 4.247, 0.000], [0.000, 0.000, 4.247]) and the atomic coordinate in the Cartesian form is [1.502,0,2.123]. In ...
2 votes
0 answers
68 views
Computing carrier concentrations for a given chemical potential range
I want to know how carrier concentrations for a given chemical potential range is computed using DOS and Fermi-Dirac distribution function from quantum ESPRESSO output. Can anyone kindly help me with ...
- 1,101
3 votes
0 answers
94 views
Problems reaching convergence for elemental As
I am running DFT+U+V calculations in a custom version of Quantum Espresso 6.5, where Hubbard U & V represent the onsite and intersite interactions. I would like to determine the formation energies ...
- 141
5 votes
0 answers
49 views
Fourier transform expression of the coulomb interaction between the sheets(graphene)
Do you know any expression which can present the Fourier form of coulomb interaction between two graphene sheets separated by vacuum (as the figure above)? Here S(w) is the transmission equation. ...
- 51
4 votes
0 answers
48 views
Boundary condition in the Linearized Augmented Plane Wave (LAPW) method
In the Linearized Augmented Plane Wave method, the radial basis functions $R_l(r;E)$ and $\dot{R_l}(r;E)=\frac{\partial }{\partial E }R_l(r;E)$ are solutions of the equations $(H-E)R_l(r;E)=0$ and $(H-...
- 51
3 votes
0 answers
58 views
Apparent asymmetry in atomic orbital coefficients for Wannier function construction in 1D
I am working on the construction of Wannier function for the 1D chain polymer, the edge-fused porphyrin chain. I came across this relevant question but unfortunately it was abandoned quite a while ago,...
- 31
1 vote
0 answers
59 views
Quantum espresso pseudopotential convergence test
I generated a pseudopotential using atomic code(Quantum_espresso_6.7/atomic/src/ld1.x) and conducted convergence test. But as below, total energy tends to oscillation as ecut goes up. (I performed a ...
- 54
8 votes
1 answer
227 views
Are there existing methods for gamma-point phonon estimation in case of large unit cells?
I'm trying to estimate some crude gamma-point phonon frequencies for a material with a large unit cell (>150 atoms). My goal is to verify some general trends (e.g., redshift) between 3-4 material ...
- 718
3 votes
0 answers
72 views
Why is it PT symmetry not TP symmetry for Kramer Degeneracy
I understand that, under time reversal symmetry $H_k$ is transformed to $H_{-k}$, and only when we are at the points where k=-k such as in 1D the 0 and $\frac{\pi}{a}$ we would have degeneracy. And if ...
- 31
5 votes
0 answers
77 views
Understanding Oxidation States and Magnetic Moments in Multivalent Transition Metal Oxides
I’m reading some papers on using density functional theory (DFT) to study oxidation states in multivalent transition metal oxides, but I’m having difficulty interpreting the oxidation-state ...
- 51
11 votes
3 answers
325 views
Is there a scriptable tool to determine whether two periodic structures are the same?
I'm doing some material search, in which I remove 2-4 atoms from a medium sized (~20 atoms) unit cell. I need to find all different combinations that are unique with respect to the translational, ...
- 718
2 votes
1 answer
122 views
To what does ibrav correspond?
Compound has cif which is cubic in structure. Upon converting it to scf using input generator, it turns to primtive cell. When it is vc-relaxed it remains cubic with a bit distortion.However, when it ...
- 161
3 votes
1 answer
275 views
In general: How to calculate effective mass from a bandstructure?
How to calculate the effective mass of silicon for the two cases: valence band maximum and valence band minimum (both at gamma point)? Any general procedure would be great to see.
- 891
9 votes
1 answer
101 views
How to determine if hybridization takes place between orbitals in an ab initio calculation using Quantum ESPRESSO?
I'm using Quantum ESPRESSO to determine the electronic properties of systems. Now I want to confirm if hybridization takes place between orbitals. I have generated density of states and projected ...
- 483
4 votes
1 answer
731 views
How to interpret defect formation energy diagram?
Why are formation energy diagrams typically plotted as a function of Fermi energy, and how should one interpret the changes in the x-axis before the charge state changes in these diagrams? Figure ...
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