Help with Monte Carlo Wang-Landau JDoS

  • Thread starter Thread starter UFSJ
  • Start date Start date
  • Tags Tags
    Monte carlo
AI Thread Summary
The discussion focuses on the Wang-Landau algorithm's ability to capture the complete joint density of states for a magnetic perovskite with specific exchange interactions. It highlights that the convergence criterion, based on flatness testing after a set number of Monte Carlo steps, does not guarantee the identification of all possible microstates. A simple example illustrates the vast number of microstates in a 20x20 Ising model, emphasizing the impracticality of sampling all microstates within a reasonable timeframe. The conversation underscores the limitations of the WL algorithm in fully exploring the microstate space. Overall, the Wang-Landau method is efficient but may not encompass every microstate in complex systems.
UFSJ
Messages
13
Reaction score
2
Hi, guys.

I have tried to write a Wang-Landau JDoS algorithm to describe a magnetic perovskite with exchange interactions J1 = 1.66 and J2 = -1.16. Then, I have a simple question: in the WL algorithm, the obtained joint density of states must have all possible E x M microstates? Since the convergence criterion in WL is just the flatness test after some Monte Carlo steps (e.g., n * 10^6), it is not guaranteed that all microstates will be identified, correct???
 
Last edited by a moderator:
Technology news on Phys.org
It is not guaranteed that you constructed all microstates. So if that's what you meant by "[not] all microstates will be identified", then you are correct.

Simple example: A 20x20 Ising model has 2^400= 2.5*10^120 microstates. Generating 10^10 microstates per second (10 per nanosecond) would mean that you would need about 10^100 years to sample all microstates. A 2D WL run for such a model will probably take a couple of seconds, maybe minutes.
 
  • Like
  • Informative
Likes Tom.G and pbuk
Dear Peeps I have posted a few questions about programing on this sectio of the PF forum. I want to ask you veterans how you folks learn program in assembly and about computer architecture for the x86 family. In addition to finish learning C, I am also reading the book From bits to Gates to C and Beyond. In the book, it uses the mini LC3 assembly language. I also have books on assembly programming and computer architecture. The few famous ones i have are Computer Organization and...
I have a quick questions. I am going through a book on C programming on my own. Afterwards, I plan to go through something call data structures and algorithms on my own also in C. I also need to learn C++, Matlab and for personal interest Haskell. For the two topic of data structures and algorithms, I understand there are standard ones across all programming languages. After learning it through C, what would be the biggest issue when trying to implement the same data...

Similar threads

Back
Top