Computational Chemistry

Structural Analysis of Handwritten Chemical Formulas

This paper proposes a strategy for interpreting handwritten chemical formulas by converting bitmap images into a dynamic structural graph of quadrilaterals. It achieves ~97% recognition on graphical elements by using recursive ‘specialists’ to identify chemical bonds and rings.

Computational Social Science
NOMINATE spatial plot showing Senate vote on Balanced Budget Amendment (1995) with legislators positioned on liberal-conservative dimension

A Spatial Model for Legislative Roll Call Analysis

This paper introduces NOMINATE, a probabilistic spatial model that recovers metric coordinates for legislators and roll calls from nominal voting data, demonstrating that a single liberal-conservative dimension explains the vast majority of Congressional voting behavior.

Computational Chemistry
Automatic chemical image recognition pipeline from raster image to structured file

Automatic Recognition of Chemical Images

This methodological paper presents a system for digitizing chemical images into SDF files. It utilizes a custom vectorization algorithm and chemical rule validation, achieving 94% accuracy on benchmark datasets compared to 50% for commercial tools.

Planetary Science
Orbital diagram showing chaotic planetary trajectories

Chaotic Evolution of the Solar System (1992)

Sussman and Wisdom’s 1992 study used the Supercomputer Toolkit and symplectic mapping to integrate the entire Solar System for 100 million years, confirming chaotic behavior with an exponential divergence timescale of ~4 million years and demonstrating that long-term planetary motion is fundamentally unpredictable.

Computational Chemistry
Chemical Literature Data Extraction: The CLiDE Project

Chemical Literature Data Extraction: The CLiDE Project

The CLiDE project (Chemical Literature Data Extraction) presents a foundational architecture for Optical Chemical Structure Recognition (OCSR). It details a three-phase pipeline - primitive recognition, text grouping, and interpretation - to convert bitmapped journal pages into chemically significant connection tables, handling complex features like stereochemistry and crossing bonds.

Computational Chemistry
Visualization of Gabor wavelets and Kohonen networks for chemical image classification

Chemical Machine Vision

This 2003 paper introduces a machine vision approach for extracting chemical metadata from raster images. By using Gabor wavelets for feature extraction and Kohonen networks for classification, it distinguishes between chemical and non-chemical images, as well as ring and non-ring systems, without requiring high-resolution inputs.

Computational Chemistry
ChemReader: Automated Structure Extraction

ChemReader: Automated Structure Extraction

This paper presents ChemReader, a fully automated optical structure recognition tool that converts raster images of chemical diagrams into machine-readable formats. It introduces a modified Hough transform for bond detection and a chemical spell checker that improves OCR accuracy from 66% to 87%.

Machine Learning Fundamentals
Diagram showing distributed representations with three pools of units (AGENT, RELATIONSHIP, PATIENT) connected via role/identity bindings

Distributed Representations: A Foundational Theory

Geoffrey Hinton’s seminal 1984 technical report that formally derives the efficiency of distributed representations (coarse coding) and demonstrates their properties of automatic generalization, content-addressability, and robustness to damage.

Computational Chemistry
Graph of the Lennard-Jones 12-6 potential showing the characteristic attractive and repulsive forces

Dynamical Corrections to TST for Surface Diffusion

This paper bridges Molecular Dynamics and Transition State Theory by applying a dynamical corrections formalism to surface diffusion, identifying a low-temperature bounce-back mechanism causing non-Arrhenius behavior.

Computational Chemistry
Embedding energy and effective charge functions for Ni and Pd from the original EAM paper

EAM User Guide: Voter's Handbook Chapter

This seminal 1994 handbook chapter serves as a definitive user guide for the Embedded-Atom Method (EAM). It details the theoretical derivation from density-functional theory, synthesizes related methods like the Glue Model, and provides a complete tutorial on fitting potentials, illustrated with a specific implementation for the Ni-Al-B system.

Computational Chemistry
Embedding energy and effective charge functions for Ni and Pd from the original EAM paper

Embedded-Atom Method: Theory and Applications Review

This seminal 1993 review systematizes the Embedded-Atom Method (EAM) as a robust semi-empirical approach for metallic systems, synthesizing theory, applications, and connections to related methods while addressing the limitations of pair potentials.

Computational Biology
Four types of protein folding energy landscapes from left to right: smooth funnel, rugged funnel with kinetic traps, moat funnel, and champagne glass funnel

Funnels, Pathways, and Energy Landscapes of Protein Folding

This seminal work resolves Levinthal’s paradox by replacing the single-pathway view with a statistical energy landscape approach. It introduces the concepts of the folding funnel, the glass transition in proteins, and the ‘stability gap’ as a design principle for foldable sequences.