Unanswered Questions
43 questions with no upvoted or accepted answers
22
votes
0
answers
248
views
Is there a software that can do derivatives with respect to user defined vibrational modes?
I'm doing some property calculations that depend on a sum of derivatives of some quantity with respect to normal vibrational modes. I was hoping to find some physical intuition relating the type of ...
- 15.9k
9
votes
0
answers
184
views
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 ...
- 939
8
votes
0
answers
109
views
Is the formula of a Dyson orbital independent of whether there is degeneracy or not in the HOMO of the neutral?
A Dyson orbital is defined as:
$$
\textrm{Dy}(x) = \int dx_1 \ldots dx_{N-1} \, (\Psi^+(x_1,\ldots,x_{N-1}))^* \, \Psi^0(x_1,\ldots,x_{N-1}, x),\tag{1}
$$
where $\Psi^0$ and $\Psi^+$ are the total ...
7
votes
0
answers
46
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 ...
6
votes
0
answers
105
views
What are the parameters in PySCF's Selected Configuration Interaction code
Dear StackExchange Members,
I'm using the native PySCF implementation of selected configuration interaction (SCI). However, I can't seem to find any documentation detailing the algorithm or various ...
- 20.1k
6
votes
0
answers
77
views
Benchmarking DFT vs Experimental Gaps - Confusion over Fundamental and Optical Gaps
Recently, I've come across discussions about the differences between fundamental (or electronic) bandgaps and optical bandgaps, with the two quantities differing mainly by the electron-hole binding ...
- 1,366
5
votes
0
answers
77
views
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 ...
- 3,770
4
votes
0
answers
27
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 ...
4
votes
0
answers
58
views
How can I estimate Total Energy using Hartree-Fock Energy?
I am using pyscf Hartree-Fock method to calculate total energy for a conventional unit cell of carbon diamond using one of the example scripts that the developers made. The script outputs the ...
- 437
4
votes
0
answers
28
views
bandstructure calculation of two-dimensional ferrovalley (RuClBr) in quantum espresso
We try to calculate bandstructure of single layer RuClBr reported in fig.4 of 'https://pubs.rsc.org/en/content/articlelanding/2016/pq/d3nr00346a/unauth'. But our obtained bandstructure is not similar ...
4
votes
0
answers
65
views
CCSD calculation between two orbitals
I am trying to calculate the CCSD energies between two orbitals. Suppose I have a system,
...
3
votes
0
answers
36
views
How to correctly set the high-symmetry point path block when there are breakpoints in the recommended path?
I watched Dr. Mohan's tutorial video, and the settings he provided are as follows:
...
- 31
3
votes
0
answers
57
views
How to compute molar Gibbs free energy (chemical potential) for single molecule using gaussian09?
I want to calculate the Gibbs free energy of single gas molecule (AsH3) using Gaussian 09, but I am confused between "Thermal correction to Gibbs Free Energy" and "Sum of electronic and ...
- 71
3
votes
0
answers
78
views
How did they calculate the indirect radiative recombination rate in this paper?
In this paper they calculated radiative recombination rates for Germanium using an effective mass model and I am trying to calculate the indirect spontaneous radiative recombination
rate related to ...
3
votes
0
answers
71
views
Reproduce Dissociation Energy of BH molecule with PySCF
I want to reproduce the bond dissociation energy of the BH molecule as stated in the book 'Molecular Electronic Structure Theory' by Helgaker et al, (chapter 8.3.1), using FCI with 1 frozen core ...
- 31