libint2 2.11.2

Python bindings for the Libint library - a high-performance library for computing molecular integrals

libint2-python

Python bindings for libint2 - a high-performance library for computing molecular integrals.

Installation

Install via pip:

pip install libint2

This installs the pre-compiled binary wheel which includes the libint2 library and standard basis sets.

Usage

import libint2
import numpy as np

# Initialize library
print(f"Using libint2 version: {libint2.LIBINT_VERSION}")
print(f"Max angular momentum: {libint2.MAX_AM}")

# Create a shell
# Shell(L, primitives, center)
s = libint2.Shell(0, [(1.0, 1.0)], [0.0, 0.0, 0.0])

# Compute overlap integrals
engine = libint2.overlap()
result = engine.compute(s, s)
print(f"Overlap: {result[0]}")

# Load a basis set
atoms = [
    libint2.Atom(8, [0.0, 0.0, 0.0]),       # O
    libint2.Atom(1, [0.0, -0.757, 0.587]),  # H
    libint2.Atom(1, [0.0, 0.757, 0.587])    # H
]
basis = libint2.BasisSet("sto-3g", atoms)
print(f"Number of basis functions: {basis.nbf}")

Features

• Pre-compiled Wheels: Available for Linux (x86_64) and macOS (x86_64, ARM64)
• Bundled Basis Sets: Includes standard basis sets (STO-3G, cc-pVDZ, etc.)
• NumPy Integration: Returns integrals as NumPy arrays

License

LGPL-3.0-or-later