MANIAC

MANIAC is a lightweight Monte Carlo simulation code written in Fortran, designed for GCMC and adsorption studies. It reads basic LAMMPS-style topology files and supports the following Monte Carlo moves:

• Translation
• Rotation
• Insertion
• Deletion
• Swap

Why the name MANIAC?

The original MANIAC computer (for Mathematical Analyzer, Numerical Integrator, and Computer) was built in the early 1950s at Los Alamos National Laboratory. It was one of the first machines used to perform Monte Carlo simulations in statistical physics and nuclear research.

Compile

To build MANIAC from source, you will need the following tools installed:

sudo apt update
sudo apt install gfortran make makedepf90

Then compile the project by running:

./build.sh

This will:

• Generate the Fortran version module from the template.
• Clean previous build artifacts.
• Rebuild the dependency file using makedepf90.
• Compile all Fortran source files with gfortran.

The resulting executable will be located at:

build/maniac

LAMMPS compatibility

MANIAC uses the same .data file format as LAMMPS for molecular topology. MANIAC assumes that the real units system is used, and that a pair style of the family lj/cut/coul/long is used.

Build the documentation

To build the documentation locally, install doxygen:

sudo apt install doxygen
sudo apt install python3-sphinx
pip install furo

Then, navigate to the docs directory and run:

cd docs
./build.sh

This will create the complete documentation in the build/html folder, that can be open using:

firefox build/html/index.html

The documentation is also visible on maniac-mc.github.io.

Examples and tests

Several example systems are provided in a separate repository: mc-topology. The code has been validated against LAMMPS and RASPA for several example cases located in mc-topology. Basic adsorption and energy tests are available in the tests/ folder.

Credit

This code was written by Simon Gravelle, who currently maintains the code, documentation, and the associated GitHub organization.