GaInt Documentation
GaInt (Gaussian Integration) is a Python package for computing molecular integrals over Primitive Cartesian Gaussian orbitals. It provides implementations of various integration schemes including Obara-Saika and McMurchie-Davidson methods.
Key Features
Multiple Integration Schemes: Support for Obara-Saika and McMurchie-Davidson recursive algorithms
Comprehensive Integral Types: Overlap, kinetic, nuclear attraction, and electron repulsion integrals
Arbitrary Angular Momentum: Support for s, p, d, and higher angular momentum orbitals
Pure Python Implementation: Easy to install and use with standard scientific Python tools
Well-Documented API: Clear documentation and examples for all functionality
Quick Start
import numpy as np
from gaint.gauss import PrimitiveGaussian
from gaint.obara_saika.overlap import Overlap
# Create two s-type Gaussian orbitals
pg1 = PrimitiveGaussian(1.0, [0.0, 0.0, 0.0], [0, 0, 0], 1.0)
pg2 = PrimitiveGaussian(1.0, [0.0, 0.0, 0.0], [0, 0, 0], 1.0)
# Calculate overlap integral
S = Overlap()
overlap_value = S(pg1, pg2)
print(f"Overlap integral: {overlap_value}")
About
GaInt was developed to provide researchers with an efficient, flexible tool for computing molecular integrals in quantum chemistry calculations. It emphasizes code clarity and educational value while maintaining computational accuracy for small to medium-sized systems.
Contents
Getting Started
Tutorial Notebooks
API