1Dchain

C++ code for the numerical simulation of one-dimensional oscillator chains and the computation of transport properties using the Transient Time Correlation Function (TTCF) formalism.

In addition, the code computes the direct time average of the same observables used in the TTCF, allowing for a systematic comparison between TTCF predictions and time-averaged quantities.

Post-processing and parameter handling are performed using Python scripts.

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Directory structure

1Dchain/
├── src/                # C++ source files
│   ├── main.cpp        # Main executable
│   ├── ode_func.cpp    # Equations of motion
│   ├── ode_solvers.cpp # Time integration schemes
│   ├── param.cpp       # Simulation parameter handling
│   ├── utils.cpp       # Utility functions
│   └── Makefile        # Build system
├── include/            # C++ header files
│   ├── ode_func.h
│   ├── ode_solvers.h
│   ├── param.h
│   └── utils.h
├── examples/           # Example input files
│   └── parametri.json  # Sample simulation parameters
├── external/           # External dependencies
│   └── json.hpp        # nlohmann/json single-header library
├── python_script/      # Python post-processing scripts
│   ├── change_parameter.py
│   └── read_TTCF_results.ipynb
├── LICENSE
└── README.md

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Compilation

The code is written in C++17 and is compiled using a simple Makefile.

From the src/ directory, run:

make clean all

This produces the executable in the same directory.

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Running a simulation

From the src/ directory:

./fput ../examples/parametri.json

The input file specifies:

• the physical parameters of the 1D oscillator system,
• numerical integration settings,
• the observables used for TTCF and time-average calculations.

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Authors

• Vincenzo Di Florio
• Davide Carbone

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License

This project is licensed under the GNU General Public License v3.0 or later.

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