The updates in Libcint 6: More integrals, API refinements, and SIMD optimization techniques.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Theoretical Chemistry

Background:

• Accurate calculation of molecular properties relies on evaluating analytical integrals.
• Gaussian type orbitals (GTOs) are fundamental basis functions in quantum chemistry.
• Efficient integral evaluation is crucial for computational performance.

Purpose of the Study:

• To present Libcint version 6.0, a library for efficient analytical integral evaluation.
• To enhance the usability and performance of quantum chemistry program development.
• To support a wide range of operators and their derivatives.

Main Methods:

• Libcint employs a uniform function signature for all integral computations.
• A code generator automates the implementation of new integrals.
• Explicit single instruction multiple data (SIMD) parallelization is used for performance.

Main Results:

• Libcint 6.0 supports overlap, Coulomb, Gaunt, Breit, attenuated Coulomb, Slater-type geminals, and Yukawa potential integrals.
• Arbitrary orders of derivatives for these operators are computable.
• The library is designed for simplicity, ease of use, and efficiency.

Conclusions:

• Libcint 6.0 provides a robust and efficient tool for quantum chemistry computations.
• The library facilitates the development of advanced quantum chemistry programs.
• Performance enhancements cater to modern CPU architectures.