27
votes
Accepted
Is ARM64 the next big thing?
It depends on what chips datacenters are using. If large data centers switch over to ARM-based processors, scientific computing will follow. Since most of our software is open source (or not far from ...
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17
votes
Is ARM64 the next big thing?
I'd expect that x86_64 will remain the architecture of choice for computing throughput for quite a while, and that there might even be a way to deliberately re-enable the Spectre/Meltdown ...
- 271
15
votes
Accepted
How are continued fractions related to quantum materials?
In the paper "A Continued-Fraction Representation of the Time-Correlation Functions", generalized susceptibilities and transport coefficients for materials are obtained using a continued-...
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14
votes
What is the minimum basis set one should use?
Different people will have slightly different opinions, so take my answer with a grain of salt. I'll try to give the minimum publishable basis sets, i.e. if you use worse basis sets than these, you'll ...
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14
votes
How do I simulate the interaction between two atoms?
EDIT Doing what you want is hard! You will need a full quantum mechanics based simulation. This is unlikely to be something you can build yourself at the current time.
Based on your new additions to ...
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13
votes
How are continued fractions related to quantum materials?
You may take a look at the Method of Continued Fractions used in quantum scattering theory—this was only formed in 19831 so is rather recent. Related is the PhD thesis by Kónya (2000)2; §3.3 ...
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13
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Is ARM64 the next big thing?
Any code that does not have core parts written in machine level code (assembly) is going to be portable to arm64 straight away; you just have to recompile the program. This is the whole point of ...
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13
votes
How do I simulate the interaction between two atoms?
How to proceed depends on how accurate you want the outcome. Throughout my answer I will provide blue buttons which demonstrate that there's entire tags in our community to address certain aspects of ...
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12
votes
How may I calculate the bond length between two atoms?
The only proper way to do it ab initio is to calculate the energy (E) for various internuclear distances (R) and then to approximate the equilibrium bond length by choosing the distance which has the ...
- 33.6k
11
votes
How do I simulate the interaction between two atoms?
Generally speaking, most work in molecular dynamics tries to simulate how actual molecules behave (i.e. quantum mechanics) and it doesn't sound like you want to go down that rabbit hole. I completely ...
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10
votes
Qualitatively, How do MEAM Potentials Work?
In short, it is a semi-empirical approach to atom/atom interaction for periodic systems.
It is based on the embedded atom method (EAM) idea where "the energy of a given atom is taken as one half ...
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10
votes
How do I simulate the interaction between two atoms?
In order to simulate two atom interaction, you have different path to follow.
One is to use Density Functional Theory (DFT) or ab initio, make a script where the distance of the atoms is decreasing, ...
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10
votes
Accepted
"Quantum protectorates" and the limits of grand unified theories
It's a very good question, and we may get several answers here from people with various different perspectives, but here is mine:
In every case so far where we are certain that computations have been ...
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8
votes
Is ARM64 the next big thing?
The main difference between ARM64 and x86_64 architectures is their core design. The x86_64 uses NUMA when more cores are involved, whereas ARM64 has a more versatile design, and can have unified ...
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7
votes
How do I simulate the interaction between two atoms?
The simplest possible atomic simulation: a noble gas
As explained by Nike Dattani, what method you use depends on what you want to simulate and why. He gives you a good roadmap for what method to ...
- 1,901
7
votes
How may I calculate the bond length between two atoms?
Unfortunately the answer to this question is much the same as your last one. What you are trying to do is hard. Very hard. Creating this would be PhD if not postdoc work and doing it well could well ...
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6
votes
How may I calculate the bond length between two atoms?
I don't know why you need atom-atom interactions in a sandbox game. My only guess is that you want to simulate or visualize the movement of molecules of some kind in real time. If your system is large ...
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5
votes
How may I calculate the bond length between two atoms?
Get your parameters from an existing force field (UFF? ReaxFF?)
People in the molecular dynamics world use established force fields to describe forces between different types of atoms. These force ...
- 1,901
5
votes
Learning how the DFT codes work
You should start off with running DFT calculations and then over time you can learn about theoretical and implementation details that interest you or are important for what you are doing. Based on ...
- 1,050
5
votes
Accepted
Qualitatively, How do MEAM Potentials Work?
To add on to the answer given by Camps above, I will explain a bit more about the Semi-Empirical nature of the potentials.
The idea is based on density functional theory, and approximates the electron ...
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5
votes
Is ARM64 the next big thing?
ARM64 may not have to be the next big thing to cause a positive change. Competition between two standards could result in extensions of either standard to improve them. We already see vendor ...
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5
votes
How are continued fractions related to quantum materials?
The continued fraction expansion is the most common way to calculate real-frequency dynamical Green's functions using Lanczos exact diagonalization. The method was introduced in this setting in ...
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4
votes
Is ARM64 the next big thing?
When I read your question I remembered a gitlab pages that list all the softwares ported to the arm architecture and their development progress.
You can find it here: https://gitlab.com/arm-hpc/...
- 1,479
4
votes
Accepted
What is the difference between computation and simulation?
For the most part, "simulations" are a specific type of "computation". This agrees with the first lines from the Wikipedia articles for computation and simulation:
"A ...
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4
votes
How may I calculate the bond length between two atoms?
The most trivial model to estimate bond lengths between two atoms is probably a simple sum of Van-der-Waals Radii. Just load a table with Van-der-Waals Radii and take the equilibrium distance for two ...
- 829
3
votes
How may I calculate the bond length between two atoms?
I don't think you are looking for anything too physically correct so I think for your purposes, you can get away with a simple morse model.
Consider which elements you would like to use, hopefully you ...
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3
votes
Accepted
Model coordination complex using GROMACS or CP2K
Here is how you can get the structure from PubChem, read the SMILES into Avogadro2, do a MMFF94 (classical) optimization, and then a single-point energy calculation using NWChem (RHF, 6-31G*). The ...
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2
votes
Research groups focused on applications vs. theory/methodology
Reasons why he switched groups for his PhD
"His reasoning for the switch is that he is determined to go to industry after PhD. In his view, an application-focused group makes it easier to ...
- 33.6k
1
vote
Accepted
I have a force in eV/Angstroms. How do I convert it so that the speed I calculate is in Angstroms/second?
Applying a force $F$ acting on a mass $m$, the acceleration according to classical mechanics is:
$$\tag{1}
a = \frac{F}{m}.
$$
Given the speed $v(0)$ at time $t=0$ and the acceleration, we can obtain ...
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Only top scored, non community-wiki answers of a minimum length are eligible