vegas

Introduction

vegas is a feature rich atomistic magnetic material simulation platform written in rust. It supports Ising and Heisenberg spins, as well as a couple of Monte Carlo algorithms, namely Metropolis and Wolff.

Vegas is meant to be used as a library to build your custom magnetic material simulation programs. That said, there's an included program that can handle generic input and can be used as a reference implementation for your own programs.

Installation

To install vegas you need to have the rust installed. Then, you can install vegas by running the following command:

cargo install vegas

If you want to install vegas as a library, you can add it via cargo:

cargo add vegas

Features

As a library

• Statistical metrics accumulators.
• Static dispatching of compund Hamiltonians.
• Pre-defined energy components: Gauge, Exchange, Anisotropy, Zeeman.
• Powerful error handling via the thiserror crate.
• Flexible instrumentation system, using dynamic dispatching.
• Support for different integration algorithms such as Metropolis.
• Parquet input output support via the parquet crate.
• Pre-defined programs: Relax, CoolDown, HysteresisLoop.

As a command line tool

You can use the toml input file format to run simulations. An example of input file is given below:

# Model definition can be Ising or Heisenberg.
model = "Ising"

# Algorithm definition can be Metropolis or Wolff.
algorithm = "Metropolis"

# You can create unit cells of different lattice types.
[sample.unitcell]
name = "sc"

# You can expand your unit cell to create larger samples.
[sample.size]
x = 10
y = 10
z = 1

# You can set periodic boundary conditions in each direction.
[sample.pbc]
x = true
y = true
z = false


# You can control the stages of the simulation.
[[stages]]
program = "Relax"
steps = 1000
temperature = 4.0

[[stages]]
program = "CoolDown"
max_temperature = 4.0
min_temperature = 0.1
cool_rate = 0.1
relax = 1000
steps = 20000

# You can define outputs to be written during the simulation.
[output]
observables = "./output.parquet"

[output.state]
path = "./state.parquet"
frequency = 1000

You can run the simulation by executing the following command:

vegas run input.toml

Contributing

Contributions are welcome! Please open an issue or submit a pull request on GitHub. There are currently some missing features that would benefit the package, such as:

• Custom exchange interaction values, we currently support only one value.
• More Hamiltonian terms (Dzyaloshinskii-Moriya, Dipolar, etc).
• More integration algorithms (Wolff, Swendsen-Wang, etc).