almaBTE v1.1 released

Post date: Jun 21, 2017 3:05:05 PM

Version 1.1 of almaBTE has been released and is freely available from

AlmaBTE is a software package that solves the space- and time-dependent Boltzmann transport equation for phonons, using only ab-initio calculated quantities as inputs. The software can currently model phonon transport in bulk crystals and alloys, thin films, superlattices, and multiscale structures with size features in the nm-μm range. Among other quantities, the program can output thermal conductances and effective thermal conductivities, space-resolved average temperature profiles, and heat-current distributions resolved in frequency and space.

In many respects, almaBTE is the successor of ShengBTE, building on its strengths and trying to extend the proven usefulness of ab-initio thermal conductivity calculations to new domains beyond single crystals in the stationary state. However, the design of almaBTE is more flexible, portable and efficient, as required by its far broader design goals.

A detailed description of the architecture of this new suite of tools and the underlying formalism can be found in this arXiv preprint.In addition to the programs described in the preprint, the almaBTE distribution contains a ShengBTE emulator specifically targeted at current ShengBTE users. This emulator is able to take unmodified ShentBTE inputs (the familiar CONTROL, FORCE_CONSTANTS_2ND and FORCE_CONSTANTS_3RD) and generate a set of outputs closely resembling those of ShengBTE. Although some of the less popular features of ShengBTE are not implemented in the emulator, for most users it will be more efficient than the original ShengBTE program. By way of example, running a thermal conductivity calculation with almaBTE for N different temperatures can be up to N times faster than with ShengBTE due to more efficient caching of temperature-independent quantities.

Another interesting development is the almaBTE database of force constants, with publication-quality sets of harmonic and anharmonic inputs for many semiconductors of theoretical and industrial interest.

We encourage ShengBTE users to try almaBTE and to contribute to its development.