Simulating Thousands of Atoms Using Linear Scaling BigDFT - Applications in Large-Scale Quantum Systems

Explore linear-scaling density functional theory (DFT) and its applications in simulating large systems containing thousands of atoms in this Lennard-Jones Centre discussion group seminar. Delve into the wavelet-based BigDFT code's implementation of linear-scaling formalism using localized support functions. Discover how this approach enables simulations of tens of thousands of atoms and offers opportunities for combining with fragment-based methods. Learn about the complexity reduction framework for analyzing electronic structures of large systems, including graph-based descriptions of fragment interactions. Examine real-world examples demonstrating the application of linear-scaling BigDFT and related fragment approaches in simulating and analyzing systems with many thousand atoms, such as OLED charge transport parameters, DNA charge analysis, and complexity reduction of a laccase enzyme.

Intro
Why DFT with 1000s of Atoms? Why do we Need QM for Large Systems?
Density Matrix Formulation
Support Function Optimisation SF Optimisation
The Algorithm Calculation Steps
Exploiting Similarity Between Fragments
Molecular Fragment Approach
OLED Charge Transport Parameters
Fragment Approach: Beyond Molecules Fragments in Extended Systems optimise SFs for embedded pseudo-fragments ⚫ can define indicators to predict the accuracy of a given setup
Example I: DNA Charge Analysis
Example II: Interactions in Laccase Complexity Reduction of Laccase Enzyme (~7000 atoms)