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Questions tagged [algorithms]

For questions about algorithms and numerical methods.

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4 votes
0 answers
41 views

How can we identify the symmetry of the molecule from its IC table?

We are given the IC table for benzene in CHARMM format, which can be written as follows: ...
Hemanth Haridas's user avatar
7 votes
1 answer
353 views

Have quantum computers been proven to speed up any matter modeling algorithm?

Personally, I think quantum chemistry is one of the most promising applications for quantum computers because the problem itself is fundamentally quantum, so there is an obvious argument why we should ...
taciteloquence's user avatar
5 votes
0 answers
55 views

How to calculate anisotropic exchange J $J_{xy}, J_{xz}, J_{yz}, J_{yx}, ...$ using 4-state mapping and DFT?

In this review, the authors present several schemes to calculate various quantities like single-ion anisotropy, DMI, and anisotropic exchange J using DFT. For instance, the DMI term in the y-direction ...
TribalChief's user avatar
  • 2,361
5 votes
1 answer
44 views

How to Balance Translational and Angular Maximum displacements in a Monte Carlo Simulation of Non-Spherically Symmetric Molecules?

I'm writing a computer simulation code to model a system of non-spherically symmetric molecules, meaning that their state are described by both angular and translational components. In typical Monte ...
Lodin Ellingsen's user avatar
9 votes
1 answer
701 views

How does charge mixing work?

When doing DFT calculations on certain magnetic materials, convergence can be difficult. This problem can be solved by changing the mixing parameters (e.g. AMIN and BMIX in the INCAR file of VASP). My ...
user avatar
4 votes
0 answers
93 views

Rys Quadrature method for integrating over Gaussian basis functions: 1D integral recursion relation [closed]

I'm trying to implement the Rys Quadrature method for integrations of Gaussians, from scratch. I'm using this paper as a reference. So, how does the overall recursion relation for evaluating 1D ...
Dmitry Govorov's user avatar
9 votes
1 answer
639 views

How to build cartesian representations of spherical Gaussian basis functions?

I'm trying to code an integral library for my own QC software from scratch. I need to use the spherical basis functions like in any other popular program. So, a D basis function is supposed to make ...
Dmitry Govorov's user avatar
7 votes
1 answer
748 views

When is coupled cluster preferred over DFT?

I know that coupled cluster is considered to provide better accuracy than DFT, but I am not sure for which materials science applications or types of molecules that this higher accuracy is considered ...
Todd Law's user avatar
  • 391
5 votes
1 answer
286 views

Define a geometry region using 'for' loop in MuMax3

I was trying to define regions using a 'for' loop. Please find the regions: ...
Arindam Samanta's user avatar
9 votes
2 answers
407 views

Evaluating the MSD of my simulation

I am running a molecular dynamics simulation of water in TIP3P, and I am storing the positions of my particles in a 2D array called relevant_positions. The number ...
megamence's user avatar
  • 4,171
5 votes
0 answers
70 views

Parallel algorithms on unstructured closed graphs [closed]

Some of the work I do in the study of discrete dislocation dynamics (a branch of materials modeling) involves topological changes on a graph: changes in the connectivity of nodes, as well as deletion ...
Daniel Celis Garza's user avatar
14 votes
2 answers
178 views

Order of scaling for different algorithms

There are many different computational methods used in matter modelling. For example: solving multi-electron Schroedinger equation, DFT with different approximations, Quantum Monte Carlo, etc. How ...
Thomas's user avatar
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13 votes
1 answer
712 views

What is the speed/time required for DFT simulations?

I am currently designing a toy model to calculate an interatomic potential (for an infinite repeating lattice) this toy model needs to scale and perform better than DFT simulations. But sadly I have ...
Highlow9's user avatar
  • 131
81 votes
6 answers
16k views

Did the 2019 discovery of O(N log(N)) multiplication have a practical outcome?

Some time ago I've read this news article, Mathematicians Discover the Perfect Way to Multiply, reporting a discovery published in 2019, where Harvey and Hoeven[1] found a algorithm able to execute ...
ksousa's user avatar
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9 votes
0 answers
128 views

Is there any literature that systematically analyzes current quantum chemistry algorithms using Big O notation for time and memory cost? [closed]

Big O notation is commonly seen in the papers on novel computational methods. However, only a few of them include rigorous analysis of the algorithm. Is there any literature that summarizes current ...
Paulie Bao's user avatar
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26 votes
2 answers
3k views

What are the "smart algorithms" applied to solve the "curse of dimensionality"?

The "curse of dimensionality" is an ubiquitous issue arising in both electronic structure and quantum molecular dynamics, which refers to the exponential scaling of computational cost with ...
Paulie Bao's user avatar
  • 3,973
44 votes
16 answers
3k views

What are some recent developments in density functional theory?

In the book Materials Modelling Using Density Functional Theory: Properties and Predictions by Feliciano Giustino, a timeline of milestones in DFT was given for achievements between 1964 and 1996: $$\...
Thomas's user avatar
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