69 questions with no upvoted or accepted answers
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### Quadrature over three Euler Angles for orientation averaging

Does anybody know about an accurate quadrature rule over three Euler angles $\theta, \phi, \chi$? I am trying to calculate the average value of an arbitrary function $f(\theta, \phi, \chi)$ for a ...
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### How to calculate t-zero temperature using Thermo-Calc- Python (TCPython) for multiple alloys?

T-zero temperature is the temperature at which the Gibbs energies of two phases are equal. Here, I wish to find the temperature at which FCC and BCC have same Gibbs energy. Thermo-Calc console mode ...
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### Benchmark Timings of Machine Learning Potentials vs Molecular Mechanics Force Fields

Machine learning is an increasingly common tool for developing force fields for molecular dynamics simulations. It's not totally clear what should be considered a machine-learning potential, but let's ...
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### Converging the potential of a dilute binary alloy system using the Coherent Potential Approximation. What troubleshooting options could I take?

I'm trying to converge a dilute fcc alloy consisting of Cu and U, with the Uranium concentration at 0.01% and the lattice parameter of Cu, using Hubert Ebert's Spin Polarized Relativistic Korringa-...
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### How to set up a local server for iQmol on macOS?

I'm trying to set up iQmol as a tool to submit calculations to Q-Chem on our lab machines to make access to it easier for OChem students. Unfortunately, it is not working properly "from the box&...
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### How to find the projected Hamiltonian for lowest flat-band in general?

In [1], starting with the bosonic Hamiltonian (Eqn. 1) for the dice lattice model with half flux density (with Ahronov-Bohm phases incorporated), H=-t\sum_{\langle j,\mu\rangle}(a^\...
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### 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 ...
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### What kind of information can be extracted from alloy microstructure images converted to Fourier space?

I have some alloy microstructure images, showing elongated grains (darker colours) and the grain boundaries (lighter colours). If I take the Fourier transform of the image, there are directional bands ...
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### Empirically determining thermostat damping factor

tl;dr Is there a way to determine an appropriate thermostat damping factor given a timestep size and a numerical integration method? I am computing a set of simulations in LAMMPS, using ReaxFF, ...
103 views

### Is there a software for macOS that can calculate collision cross-sections involving molecules with several atoms?

What macOS software currently can be accessibly used to calculate collision cross section using the geometries obtained from DFT? In my case, Q-Chem is used for geometry optimization. The goal is to ...
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### What are the advantages of different point defects calculation tools?

As far as I know, there are mainly PyCDT, PyDEF, pylada and some part of pymatgen. As a new user to those tools, which one would be a good choice? pycdt: Python Charge Defects Toolkit (PyCDT) is a ...
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### How to understand dynamical spin structure factor?

A newish area of interactions between quantum Monte Carlo (QMC) and experiments is in spin spectra. Recent improvements in stochastic analytic continuation have made it much easier to compare/extract ...
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### How exactly does one compute the vibrational density of states from the output of a molecular dynamics simulation?

There are many things that can be done with the output of a molecular dynamics simulation, but one of the more powerful things is the ability to compute the vibrational density of states (or the ...