1. About

1.1. What is ALAMODE?

ALAMODE is an open source software designed for analyzing lattice anharmonicity and lattice thermal conductivity of solids. By using an external DFT package such as VASP and Quantum ESPRESSO, you can extract harmonic and anharmonic force constants straightforwardly with ALAMODE. Using the calculated anharmonic force constants, you can also estimate lattice thermal conductivity, phonon linewidth, and other anharmonic phonon properties from first principles.

1.2. Features

General

  • Extraction of harmonic and anharmonic force constants based on the supercell approach

  • Applicable to any crystal structures and low-dimensional systems

  • Accurate treatment of translational and rotational invariance

  • Interface to VASP, Quantum-ESPRESSO, OpenMX, xTAPP, and LAMMPS codes

  • Mainly written in C++, parallelized with MPI+OpenMP

Harmonic properties

  • Phonon dispersion

  • Phonon DOS, atom-projected phonon DOS

  • Two-phonon DOS

  • Vibrational thermodynamic functions (heat capacity, entropy, free energy)

  • Mean-square displacement

  • Animation and visualization of phonon modes (requires VMD or XCrysDen)

  • 3-phonon scattering phase space

  • Phonon-isotope scattering rate

  • Participation ratio for analyzing the localization of phonon modes

Anharmonic properties

  • Grüneisen parameter via cubic force constants

  • Lattice thermal conductivity by BTE-RTA

  • Cumulative thermal conductivity

  • Phonon linewidth due to 3-phonon interactions

  • Phonon frequency shift due to 3- and 4-phonon interactions

  • Temperature-dependent effective potential method

  • Self-consistent phonon (SCPH) calculation

  • Anharmonic vibrational free-energy

  • Structural optimization at finite temperatures based on SCPH or QHA.

Note

The structural optimization of the current version CANNOT be used with thermal conductivity calculations or bubble corrections. The standard SCPH dispersion and thermodynamic properties are correctly calculated for relaxed configurations.

Note

The tutorials for the structural optimizations are temporarily provided in https://github.com/r-masuki/StructuralOptimizationTutorial. The tutorial for the new feature will be included in this page in the future.

1.4. License

Copyright © 2014-2023 Terumasa Tadano

This software is distributed under the MIT license. See the LICENSE.txt file for license rights and limitations.

1.5. How to Cite ALAMODE

Please cite the following article when you use ALAMODE:

ALAMODE papers

Reference number

Features

[1]

General citation paper for all features of ALAMODE

[2]

Self-consistent phonon (SCP) method (MODE = SCPH)

[3]

Anharmonic free energies within SCP or improved SCP (ISC)

[4]

SCP-based structural optimization or PERIODIC_IMAGE_CONV = 1 (default) in the alm code

[5]

QHA-based structural optimization

References

1.6. Issues & Bug report

In either case, please search the previous questions and read FAQ page of this document before asking.

1.7. Acknowledgment

This project is/was partially supported by the following projects:

  • Grant-in-Aid for Scientific Research (C) (21K03424)

  • Grant-in-Aid for Young Scientists (B) (16K17724)

  • Grant-in-Aid for Scientific Research on Innovative Areas ‘Materials Design through Computics: Complex Correlation and Non-Equilibrium Dynamics’. (http://computics-material.jp)

1.8. Author & Contact

Research Center for Magnetic and Spintronic Materials (CMSM),
National Institute for Material Science (NIMS),
Japan