Set up a File Server on Windows
In this post, I will be noting down how to use Dufs [1] for setting up a file server on Windows 11. Originally, I was using gohttpserver which is no longer maintained, and Dufs is one of the recommended options on the gohttpserver GitHub [2]. First, we need to install...
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Real Spherical Harmonics Visualization
Taking the \(Y_4^3\) function as the example, the full mathematical form of the function is,
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Goldstone Mode and Spontaneous Symmetry Broken
Some Follow-up Notes on Preferred Orientation and Texture
In one of my previous posts, I had some notes about the preferred orientation and texture and the two typical ways to represent them [1]. In this post, I am trying to put down some follow-up notes about the topic, hoping to add some more understanding of the topic.
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Einstein and Debye Model for Specific Heat
In the low temperature region, the Dulong-Petit describing the specific heat \(C_V\) as \(3R\) fails – \(C_V\) will approach 0 while \(3R\) stays a constant across the whole temperature range. Fundamenally, this is due to the failure of the equipartition theorem in the low temperature region. Einstein gave the problem...
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About the Metropolis Monte Carlo Method
Bond Valence Energy Landscape Calculation with the BondStr Program in Fullprof Suite
Running GSAS-II Scriptable Refinement
GSAS-II is a powerful software for analyzing the crystallographic structure from diffraction data. It is written in Python, with some underlying routines in Fortran and C++. Conveniently, it provides the scriptable interface so that we can perform the refinement in a programming way. This is pretty handy when some batch...
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Installation of GSAS-II on Linux
GSAS-II is a powerful software for analyzing the crystallographic structure from diffraction data. It is written in Python, with some underlying routines in Fortran and C++. Here I am sharing my working pipeline to get GSAS-II working on my Linux machine of Ubuntu distro. FYI, here below is listed my...
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Publish Apps on MacOS
Notes on Selection Rule for Transition between Energy Levels
When a physical system is absorbing or emitting electromagnetic radiation, there will be a transition happening between the quantum energy levels of the system. The selection rule determines whether or not such a transition can happen. It is a typical topic in quantum mechanics textbook and it is not the...
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Local Development of GSAS-II -- New Instructions
Here in this post, I will put down the instructions for setting up the local developing environment for GSAS-II. See the legacy instructions in my previous post here for the old version of the source codes.
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Local Development of GSAS-II -- Deprecated Instructions
GSAS-II is a powerful software for analyzing the crystallographic structure from diffraction data. It is written in Python, with some underlying routines in Fortran and C++. It is possible to grab the source codes of GSAS-II, develop and test it locally. This post covers the steps to set up the...
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Notes on the development environment setup for RMCProfile
Development environment setup for RMCProfile on Windows
Description of Magnetic Structure with Propogation Vector
A brief summary of the early superconductivity development
Tips on Wordpress Setup
Output of the Reduced Time-of-Flight Powder Diffraction Bragg Data
FAQs about Mantid – Yuanpeng's Collection
Van Hove Function
The Van Hove function describes the time dependent pair correlation between atoms,
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Stacking Faults
Close packing means that if assuming hard sphere model for atoms, we would have as much dense packing of those hard spheres as possible. Specifically, this refers to the packing of equal spheres (radius being equal). Normally, we have two types of close packing, the hexagonal close packing (HCP) and...
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Preferred Orientation and Texture
Normally for a powder sample, we are assuming that we have a uniform distribution of orientation of those small crystalline samples, meaning that we have many small crystalline pieces of the sample and their orientation in space is uniform. As such, in the measured powder diffraction pattern, the peak intensities...
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Dirac Equation
Introduction
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Amazon AWS S3 setup
Introduction
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Notes on using VSCode
This post is a collection of notes for useful setups, tricks and utilities in VSCode, as one of the popular IDEs in the market, along with
Sublime Text, Atom, JetBrains, and so many to name.
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Set up a Flarum forum on VPS
Construct lattice vectors from lattice parameters
In crystallography, quite often we would use the 6 lattice parameters to describe the unit cell, namely, a, b, c, \(\alpha\), \(\beta\) and \(\gamma\). In some cases, we would also need to construct those lattice vectors (\(\vec{a}\), \(\vec{b}\) and \(\vec{c}\)) in Cartesian coordinate system. For example, when we want to...
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Photoshop基于图层生成动画
将一系列图片导入到Photoshop里，然后基于图层生成动画，即每一个图层为生成动画的一帧，下面给出的是详细的操作步骤，
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Set up our own search engine with Yacy
The fundamental idea of web searching is through web crawling, critical information about the website and the embedded links in the crawled website can be obtained. Based on the crawling results, a ranking algorithm could be applied, based on which one can search the website using keywords. Nowadays, we get...
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Resize Oracle VPS volume
When setting up Oracle cloud instance, we would give the instance an initial allocation of volume, and later on we might find that the initial volume size is not enough as we install more and more services into our VPS. In such a situation, we may want to expand the...
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Find out symmetry from RMC fitted supercell
In the reverse Monte Carlo (RMC) modeling, there is no constraint of symmetry exerted on the model. Once the initial unit cell is expanded to a supercell, the symmetry constraint will be removed and the model will be purely driven by the data together with some other physical or chemical...
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Size & strain effect and preferred orientation in diffraction
Size effect
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Thermal background in pair distrubtion function (PDF)
This post discusses the thermal background of a pair distribution function (PDF), taking the paper by K. Page, et al. [1] as the reference and noting down several aspects that are critical for understanding the topic. The paper was originally reporting an alternative way for coping with the incoherent inelastic...
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Typical Science Papers with RMCProfile
This blog lists out several typical research papers with RMCProfile that I myself was involved.
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Notes on using Jupyter book
Notes on difference Fourier map
Reversing the transformation from reciprocal space to real space given an experimentally measured diffraction pattern is difficult in practice since the phase information is lost in the experimental diffraction measurement and we are left with only the intensities of the Bragg spots. The Fourier map approach is one of commonly...
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Notes on implementing search in Jekyll site
Notes on Slack App Setup
Send message to Slack with Python
To set up for sending message to Slack using Python, we can refer to Ref. [1]. Most of the instructions in the reference
would work out, with several glitches and thus necessary adjustments.
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Notes on Total Commander Setups
Tips & Tricks
This post is a collection of notes of tips and tricks for Total Commander setups. This is a software as an alternative
to the file explorer on Windows. It allows double column management and operations, making life much easier in terms of
file and directory operations.
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Notes on GSAS-II
Tips & Tricks
This post is a collection of notes, tips and tricks for using GSAS-II.
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Notes on slurm server setup
Tips & Tricks
This post is a collection of notes of tips and tricks when trying to set up slurm server on Ubuntu 20.04 focal.
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Notes on Jupyterhub server setup
Tips & Tricks
Notes on twin paradox
This post is my notes for reading an online article published on Scientific American about resolving the twin paradox purely in the special relativity framework. Refer to Ref. [1, 2] for the original article.
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Notes on magnetism - IV
About stray and demagnetization field
In this post, some basics about the stray and demagnetization field will be covered. The post originates from reading the book by Stöhr – Ref. [1].
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Image effect in web page
CSS + Javascript for basic image effect in web page
In the index page of current blog, we have a picture shown as below - if we hover the mouse over the image, it will change to another picture and also as we move our mouse, the image will tilt along with the mouse moving.
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Math equation in Jekyll
Notes on inclusion of equation in GitHub pages
Copy of code snippet in Jekyll
Notes on inclusion of a button for copy code snippet in GitHub pages
Notes On Isotropy Subgroup
Key notes for reading the lecture notes by Stokes on isotropy subgroup
Figure. 1. Isotropy subgroup [1].
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Size effect in RMCProfile
Implementation of nano-size effect correction for modeling PDF
Figure. 1. Simulation box for bulk (left) and nano (right) systems.
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Derivation of neutron incoherent scattering length
Figure. 1. Neutron scattering length table by NIST [1].
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Notes on topological physics
Image reproduced from Ref. [5].
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Notes on Ising model
Ernst Ising (Left) and Wilhelm Lenz (Right) - Ising was Lenz’s student and the Ising model was claimed (by Ising himself) to be originated by Lenz but named after Ising.
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Management of Jupyter kernels
Intro to Sphinx
Documentation with docstring in Python
Jupyterlab kernel setup
Conda environment to be used as Jupyterlab kernel across users
Notes on magnetism - III
Various physical quantities describing magnetic field
About electron spin
Why do we have spin half for electrons?
Illustration for Stern-Glach experiment [1].
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Configure RMCProfile
Some tips for configuring RMCProfile on Unix/Linux system
Configuration on Linux system
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Notes on Jekyll
building site with Jekyll locally
Notes on kernel density estimation
With a collection of data, we may want to extract or estimate the underlying distribution model. For example, we have the collection of house price in a certain area, we want to have an idea about how the house price in that area is distributed. However, without a priori knowledge...
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Notes on RSA algorithm
Image reproduced from Ref. [9].
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为什么不能通过让海水不断降温从而获取无尽的能量？
Notes On Temperature
Notes on occupational short-range ordering in crystal
When multiple atomic species (including vacancies) coexist on the same crystallographic site, it immediately brings up a question - say, we have species A and B sharing the same site, then do we have clustering of A and B in separate domains, or do we have A and B preferring...
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Notes on Sublime Text 3
Key binding configuration issue
When Fourier transform meets total scattering
Build package with conda recipe
A minimal working example
There are indeed instructions and tutorials about how to build conda packages (which we can then install easily through conda, e. g. by simply executing ‘conda install …’ from command line) with conda recipe. However, as a beginner to conda build, it was really difficult for myself to find the...
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Install DISCUS version 6 on Windows 10
Problem & solution
Notes on CUDA programming II
Matrix multiplication
First of all, we may need a review for the very basic CUDA programming and GPU execution principle. Here, I want to use the diagram below to demonstrate the threadings on GPU with a very simple array addition operation example.
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Notes on CUDA programming I
Preparation
To understand and implement CUDA codes in practice, the very first step is to understand the allocation of threads on GPU. Fundamentally, threads are basic units on GPU where computation can happen in a parallel way. To the first level, threads are grouped into blocks, either in a 1D, 2D...
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Notes on magnetism - II
Magnetic ions in crystals
Talking about the magnetism of ions in crystals naturally brings us out of the atomic physics picture which we previously based ourselves in when discussing the free atom and ions (see previous note by clicking me!). Also, for sure we should turn to the many-electron scheme instead of a single-electron...
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Notes on magnetism - I
Magnetism of free atoms and ions
To understand the magnetism of free atoms and ions, we may go through several stages, as follows,
Hartree approximation - electrons are treated in a non-interactive manner.
Beyond Hartree - interaction between electrons is taken into account.
Spin-orbital coupling.
Hyperfine interaction - the interaction between electrons and nucleus.
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About Coriolis force
First, a comprehensive GIF animation demonstrating the basic ideas of Coriolis force is presented.
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Notes on special relativity
A silent refrigerator
The working principle of Einstein’s refrigerator
All refrigerators running with gas relies on the principle that the evaporation of liquid to its corresponding gas form will take heat from surroundings. After evaporation, the gas should be liquefied back to liquid form to finish the cycle, and of course, the process of liquefaction will emit heat. That’s...
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