Bridging the Gap Between Theory and Experiment with Machine Learning Open Access

Chen, Xu (Spring 2026)

Permanent URL: https://etd.library.emory.edu/concern/etds/j3860865w?locale=en
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Abstract

Accurately linking theoretical predictions with experimental measurements remains a central challenge in computational chemistry. Quantum mechanics provides a rigorous foundation for describing molecular systems, yet its direct application to realistic chemical environments is often computationally prohibitive. Machine learning has emerged as a powerful complement, capable of improving efficiency and predictive performance; however, many models sacrifice interpretability and robustness, particularly in noisy or data-scarce experimental settings. Overcoming these limitations requires approaches that enhance predictive accuracy, interpretability, transferability, and accessibility. In this dissertation, I address these challenges from several complementary perspectives. First, Δ-machine learning is employed to correct systematic biases in implicit-solvent (time-dependent) density functional theory calculations, thereby reducing functional dependence and improving agreement with experimental redox potentials and absorption energies. Second, to overcome the scarcity of experimental data, I develop a domain-adversarial framework that combines abundant simulated spectra with limited experimental measurements to detect thermodynamic phase transitions from angle-resolved photoemission spectroscopy. Applied to cuprate superconductors, this framework achieves over 97% accuracy in identifying phase transitions from experimental spectra. Third, I develop ACES-GNN, a graph neural network trained with activity-cliff explanation supervision that simultaneously improves predictive performance and interpretability. Finally, I develop AutoSolvate-Agent, a large-language-model-driven autonomous system that automates simulation setup, error recovery, and interactive interpretation for advanced solution-phase quantum chemistry.

Table of Contents

Chapter 1. Introduction ................................................. 1

 1.1 Computational methods for molecular property prediction .......... 2

 1.2 Representation of molecular and material system ................. 11

 1.3 Interpretability of machine learning models ..................... 19

 1.4 Outline of the dissertation ..................................... 24

Chapter 2. Δ-Machine learning for quantum chemistry prediction of 

solution-phase molecular properties at the ground and excited states ... 28

 2.1 Introduction .................................................... 29

 2.2 Methods ......................................................... 31

 2.3 Results and discussion .......................................... 39

 2.4 Conclusions ..................................................... 54

 2.5 Acknowledgments ................................................. 55

Chapter 3. Detecting thermodynamic phase transition via explainable 

machine learning of photoemission spectroscopy ......................... 57

 3.1 Introduction .................................................... 58

 3.2 Methods ......................................................... 61

 3.3 Results and discussion .......................................... 67

 3.4 Conclusions ..................................................... 79

 3.5 Acknowledgments ................................................. 81

 3.6 Appendix ........................................................ 81

Chapter 4. ACES-GNN: Can graph neural network learn to explain activity 

cliffs? ............................................................... 90

 4.1 Introduction .................................................... 91

 4.2 Methods ......................................................... 95

 4.3 Results and discussion ......................................... 102

 4.4 Conclusions .................................................... 115

 4.5 Acknowledgments ................................................ 116

Chapter 5. AutoSolvate-Agent: an autonomous agent for GPU-accelerated 

solution-phase quantum chemistry ...................................... 118

 5.1 Introduction ................................................... 118

 5.2 Methods ........................................................ 122

 5.3 Results and discussion ......................................... 125

 5.4 Conclusions .................................................... 130

 5.5 Acknowledgments ................................................ 130

Chapter 6. Conclusions and perspectives ............................... 131

Bibliography .......................................................... 137

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