Questions tagged [mathematical-modeling]
Questions related to mathematical modeling of materials systems.
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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 ...
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A viscoelastic material with nonconvex memory kernel?
The title is basically my question. Viscoelastic materials are characterized by a constitutive equation between stress and strain involving a convolution integral. This integral is weighted with a ...
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Database (or table) of functions obeying symmetry properties of space groups
I'm looking for a table or database containing mathematical functions that belong to crystallographic space groups by having the same symmetry elements.
Imagine a 2D square planar lattice. It has a 4-...
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How can I properly plot this .cube file in Python?
Motivation for Post: I saw a question about how to plot a .cube file recently on the Mathematica & Wolfram Language Stack Exchange. It was marked "off-...
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How can one determine the time-step for imaginary time evolution?
The real-time evolution of a quantum system described by the state $\psi(t)$ is formally given by,
$$ \psi(t+\Delta t) = \exp^{- i \hat{H} \Delta t / \hbar} \psi(t)\tag{1}$$
For dynamical simulations ...
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Gauge constraint in the definition of the Z2 invariant
Cross-posted at Physics.SE.
In Fu and Kane's paper from 2006, the authors define the $\mathbb{Z}_2$ invariant for time-reversal invariant topological insulators as an obstruction to Stoke's theorem,
$$...
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Why are some point groups for single atoms listed as Oh in the CCCBDB?
Does anyone know why the CCCBDB database lists the tin cation and antimony atom as having the Oh point group (please see the screenshot below from CCCBDB when I look at "All molecules sorted by ...
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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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Are there any software packages to find the minimum number of constraints to fix a molecule structure?
I wanted to know if there are any modules or packages which help in identifying the bonds which should be fixed to make the molecule rigid. For example in $\ce{H2O}$ there are just three (trivial), $\...
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Proof that equilibrium phase fraction(s) is a continuous function of composition
It seems that the equilibrium phase fractions (i.e., relative amounts of phase A1, A2, ..., Aq for a system in which there are q total phases) as a function of composition (for a constant pressure and ...
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How can I compute the longest relaxation time?
Cross-posted on Stats.SE and on SciComp.
In the case of Monte Carlo simulations:
Autocorrelation Time ($\tau_{\text{int}}$): A measure of how many steps are needed for the correlations in the chain ...
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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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A problem to simulate the kinetic energy operator using some field going through a crystal
We know about a differentiation and integration operations and also other ones can be simulated by an analog way using electric circuits with operational amplifiers (here are articles of the ...
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Difference between Phase Diagram and Convex Hull
in literature I sometimes see a mixed use of the words Phase Diagram and Convex Hull. However from my current knowledge, there are some differences between them.
A phase diagram views the difference ...
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What kind of chemistry background to get to pursue computational chemistry from an IT background?
What kind of chemistry background to get to pursue computational chemistry from an IT background?
I have no background in chemistry, and there might be others like me. But I know about computer models....
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