Unanswered Questions
27 questions with no answers
22
votes
0
answers
248
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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
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
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
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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
3
votes
0
answers
94
views
What is a relaxed reduced density matrix?
I am trying to understand how to calculate electronic properties using reduced density matrices from electronic structure calculation. So far, I understand (I think) that for the expectation value of ...
3
votes
0
answers
26
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How to get energy gap change at specific high symmetry points during ab initio molecular simulations？
I want to check the energy gap change during finite temperature ab initio molecular simulations. The results may look like this picture:
How can set aimd simulation to get this result in VASP?
- 579
3
votes
0
answers
106
views
Creating Monoclinic boxes with Packmol?
I am trying to reproduce this paper and the unit cell for the system is Monoclinic. I have already generated the surface, and now need to generate the waterbox that is placed in contact with the ...
3
votes
0
answers
151
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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. ...
2
votes
0
answers
81
views
How to adapt Einstein summation subscripts from 3-Index to 4-Index tensors in Numpy's einsum?
I am trying to apply frozen core approximation in order to get the effect of the forzen core orbitals on the 1-electron and 2-electron Hamiltonian. According to the notes on Page 28, the electronic ...
2
votes
0
answers
41
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Is it reasonable to extract the Schottky barrier height from the zero-bias transmission spectrum?
The following question is based on discussions What's meaning of zero energy reference point in the energy-axis of zero-bias transmission spectrum extracted by sisl.get_sile('systemlabel.TBT....
- 167
2
votes
0
answers
32
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How to start a unrestricted hartree fock (UHF) calculation with a custom guess in PySCF?
At first I want to do a UHF calculation of Li$_2$ dimer with spin=6 which shall give a sequence of $\sigma_{1s} \sigma^*_{1s} \sigma_{2s} \pi_{2p_x} \pi_{2p_y} \pi_{2p_z}$ (ordering might be wrong) ...
2
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0
answers
41
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siesta: Why is the current 0 for V < 0.8?
I met same problem in this questionsiesta: current-voltage threshold value is not consistent with the band gap value
After I finished this tutorial https://github.com/zerothi/ts-tbt-sisl-tutorial/tree/...
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