abacuslite

Introduction

A lightweight ABACUS calculator and I/O plugin for ASE. It packages ABACUS's ASE interface as an independent, pip-installable project. Existing abacuslite imports keep working, and ASE does not need patching.

Use it for energy, forces and stress in ASE workflows, or to read and write ABACUS files without launching an engine. The current develop output format and the 3.10.x LTS format are supported. The fixed-cell socket calculator requires an ABACUS build with the socket driver.

Stable release: 1.2.1 on PyPI. Publication evidence and artifacts are tracked in the release record below. Version 1.2.1 exposes explicit no-entropy energy metadata for ATST reference comparisons while preserving standard ASE energy values. The 1.x line was tested with ABACUS develop v3.11.0-beta10 and LTS v3.10.1. See the compatibility record for the exact snapshots and current checks, and the release record for artifact and publication status.

Key features

• Lightweight: an ASE plugin; no ASE core changes are required.
• Engine compatibility: each calculator selects latestio or legacyio from the configured ABACUS version.
• ASE workflows: energy, forces and stress for relaxation, MD, NEB, band structure and DOS through ASE.
• Socket support: AbacusSocketIO provides fixed-cell i-PI calculations.
• Pure I/O: read and write INPUT, STRU and KPT, and read completed output without launching ABACUS.

Installation

Requires Python 3.10+ and ASE 3.28+ (<4):

python3 -m venv .venv
source .venv/bin/activate
python -m pip install 'abacuslite==1.2.1'
python -m pip check

Pip installs ASE, NumPy and seekpath. ABACUS, pseudopotentials and orbital files are supplied separately. Tested engine snapshots are listed in supported versions.

Quick start

Read an existing input file without an engine:

from abacuslite.io.generalio import read_input

print(read_input("INPUT"))

Run a short SCF calculation:

from ase.build import bulk
from abacuslite import Abacus, AbacusProfile

atoms = bulk("Si", "diamond", a=5.43)
profile = AbacusProfile(
    command="mpirun -np 2 abacus",   # or the actual ABACUS binary path
    pseudo_dir="/path/to/PP_ORB",
    orbital_dir="/path/to/PP_ORB",
)
atoms.calc = Abacus(
    profile=profile,
    directory="scf-run",
    pseudopotentials={"Si": "Si_ONCV_PBE-1.0.upf"},
    basissets={"Si": "Si_gga_8au_100Ry_2s2p1d.orb"},
    inp={"basis_type": "lcao", "gamma_only": True, "scf_thr": 1e-3},
)
print(atoms.get_potential_energy())

Recent ABACUS develop builds may name the executable abacus_basic_para instead of abacus; point command at the actual binary. Most shipped examples use genelpa; if your build lacks it, set ks_solver to an available solver.

Examples

The source release includes eleven examples. A suggested learning path is SCF, relaxation or MD, then the more specialized workflows. See the usage guide for assets, engine features, cleanup behavior and the complete table.

Documentation

Authors

• Yuyang Ji (@jiyuyang)
• Zhenxiong Shen (@Shen-Zhen-Xiong)
• Yike Huang (@kirk0830)
• Zhaoqing Liu (@QuantumMisaka)

Contributors

• Jianrui Geng (@Phorbol) — fixed-cell i-PI socket driver and AbacusSocketIO (ABACUS #7609).

Acknowledgments

Thanks to the ABACUS community for their support and contributions.

License

Licensed under LGPL-3.0-only. Original attribution and ATST-derived adaptations are recorded in UPSTREAM.md.

Contact

Report issues at QuantumMisaka/abacuslite.