ACMD Seminar: Calculating Molecular Integrals in Polyatomic Molecules: Developing a 3D Adaptive Grid Based on Atomic Weighting Functions | NIST

Title: Calculating Molecular Integrals in Polyatomic Molecules: Developing a 3D Adaptive Grid Based on Atomic Weighting Functions

Summary:
Quantum chemists use Gaussian basis sets to expand molecular orbitals because they allow for efficient calculation of molecular integrals. However, these basis sets are inadequate for representing the oscillatory functions needed to describe the molecular continuum. This requires using B-splines and/or finite element functions, necessitating 3D numerical integration.

Dr. Barry Schneider from NIST presented a talk on developing a 3D numerical integration approach for polyatomic molecules. He explained why Gaussian functions are the preferred choice for standard quantum chemistry calculations and discussed the decomposition of unity method for numerical integration. The talk also covered the selection of atomic weight functions and provided numerical examples.

The video of the talk is available to NIST staff in the Math channel on NISTube.

Source: https://www.nist.gov/itl/math/acmd-seminar-calculating-molecular-integrals-polyatomic-molecules-developing-3d-adaptive

Keywords: basis sets, Gaussian functions, numerical integration, electronic density, polyatomic molecules

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