YingXing Cheng
PhD Degree in Physics
Development of frequency-dependent polarizable force fields, Time-Dependent Density Functional Theory (TDDFT), Computational Material Science, Software Engineering, and Machine Learning
Education
2023-now: PostDoc, Numerical Mathematics for High Performance Computing (NMH), University of Stuttgart, Stuttgart, Germany
2019-2023: PhD Degree, Faculty of Science: Physics, Ghent University, Ghent, Belgium
2016-2019: Master's Degree, Materials Science and Engineering, Beihang University (BUAA), Beijing, China (GPA: 3.60 of 4.00)
2012-2016: Bachelor's Degree, Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, China (GPA: 3.72 of 4.00)
Research
2020-2023
Development of Frequency-Dependent Polarizable Force Field: ACKS2\(\omega\) Model
Created ACKS2\(\omega\), a frequency-dependent extension of the polarizable force field ACKS2, for predicting dynamical response properties of finite systems. Validated the method's accuracy by evaluating absorption spectra of 42 organic and inorganic molecular monomers, showing good agreement with time-dependent density functional theory (TDDFT) calculations. Computed \(C_6\) dispersion coefficients, closely reproducing TDDFT reference values. The parameters in this model are computed as simple expectation values of an electronic wavefunction, and the hardness matrix is entirely reused from ACKS2 using an adiabatic approximation. These findings confirm that ACKS2\(\omega\) provides a solid connection between quantum-mechanical descriptions of frequency-dependent response and computationally efficient force-field models.
2020-2023
Investigating the Role of Fluctuating Charges in Molecular Linear-Response Properties Using ACKS2\(\omega\) Model
Explored the contribution of fluctuating charges to the dynamic linear response properties of finite systems, focusing on dipole polarizability (\(\alpha\)) and \(C_6\) dispersion coefficients. Discovered that fluctuating charges are the dominant contributor to molecular \(\alpha\) anisotropy, with charge transfer playing a significant role in long-chain or \(\pi\)-conjugated systems. For anisotropic \(C_6\) coefficients, fluctuating charges contribute significantly, while dipole-dipole interactions mainly compensate for anisotropy. These findings offer insights into the role of fluctuating charges in determining dynamic linear-response properties and contribute to the development of accurate polarizable force fields.
2019-2020
Comprehensive Database of Atomic Dipole Polarizabilities with Relativistic and Correlation Effects Using DIRAC Program: ACKS2\(\omega\) Parameterizations
Applied the finite-field method to calculate static dipole polarizability for main-group and transition-metal elements. Demonstrated that scalar-relativistic effects are predominant for Groups 1-2 and 11-12 elements, while spin-orbit coupling effects are negligible in dipole polarizability calculations across all groups, except for Groups 13-18. Gained insights into the fundamental properties of main-group and transition-metal elements, emphasizing the importance of accounting for various factors in dipole polarizability calculations. This work can be used to parameterize ACKS2\(\omega\) for polarizable force field development.
2017-2018
Developed a Framework Combining Genetic Algorithm and Cluster Expansion Method for Predicting Atomic Structures of Materials with Point Defects
As the leading developer, designed a framework combining genetic algorithm, cluster expansion (CE) method and first-principles supercell method called "pyGACE" that can effectively locate the ground-state or metastable states of point-defect-containing materials, including alloyed/doped systems. The efficiency of pyGACE was demonstrated by searching for stable structures of two systems, i.e., oxygen-vacancy-containing \(\mathrm{HfO}_{2-x}\) and Nb-doped \(\mathrm{SrTi}_{1-x}\mathrm{Nb}_x\mathrm{O}_3\), and identifying more stable structures than those available in the literature.
2017-2018
Developed an Automatic Workflow of Vacancy-Formation-Energy Calculation and Bonding-Environment Analysis Using ANN
As the leading developer, designed a framework for automatically computing vacancy-formation energies (\(E_f\)) and analyzing the bonding environment concealed in \(E_f\) using an artificial-neural-network (ANN) method. Ge vacancy in phase-change memory material GeTe was used as a case study, and contributions of different bondings to the energy of the system were obtained, based on which the bonding between atoms was further analyzed.
2016-2017
Studied the Electronic Structure of Strongly Reduced (\(\overline{1}11\)) Surface of Monoclinic HfO\(_2\)
Using first-principles calculations, the surface oxygen-vacancies (Vos) induced electronic-structure variation of HfO\(_2\) was studied to explore its potential applications in surface-controlled electronic devices. Through comprehensive calculations of Vos formation energies and electronic structure analysis, a conductivity-stability dilemma of the Vo-chains was found, providing a guideline for understanding and designing electronic devices based on HfO\(_2\) surface.
Publications
[1] YingXing Cheng, Toon Verstraelen. The significance of fluctuating charges for molecular polarizability and dispersion coefficients. J. Chem. Phys. 159, 094111, (2023). https://doi.org/10.1063/5.0163842
[2] YingXing Cheng, Toon Verstraelen. A new framework for frequency-dependent polarizable force fields. J. Chem. Phys. 157, 124106, (2022). https://doi.org/10.1063/5.0115151
[3] YingXing Cheng, Linggnag Zhu, Guanjie Wang, Jian Zhou, and Zhimei Sun. Vacancy formation energy and its connection with bonding environment in solid: A high-throughput calculation and machine learning study. Comput. Mater. Sci. 183, 109803, (2020). https://doi.org/10.1016/j.commatsci.2020.109803
[4] YingXing Cheng, Linggang Zhu, Jian Zhou, and Zhimei Sun. pyGACE: Combining the genetic algorithm and cluster expansion methods to predict the ground-state structure of systems containing point defects. Comput. Mater. Sci. 174, 109482, (2020). https://doi.org/10.1016/j.commatsci.2019.109482
[5] YingXing Cheng, Linggang Zhu, Yile Ying, Jian Zhou, and Zhimei Sun. Electronic structure of strongly reduced (\(\overline{1}11\)) surface of monoclinic HfO\(_2\). Appl. Surf. Sci. 447, 618, (2018). https://doi.org/10.1016/j.apsusc.2018.03.234
Unpublished Papers
[1] YingXing Cheng. Relativistic and Electron Correlation Effects in Static Dipole Polarizabilities for Main-Group Elements (2024). (Submitted to PRA)
[2] YingXing Cheng, Eric Cancès, Virginie Ehrlacher, Alston J. Misquitta, and Benjamin Stamm. Multi-center decomposition of molecular densities: A numerical perspective (2024). https://arxiv.org/abs/2405.08455
Software
Developed a package that calculates long-range correlation energy, taking into account charge and dipoles. The package includes implementations for all ACKS2\(\omega\) variants, as well as ab-initio implementations such as HFsrDFT and various RPA energy models. While the package is not yet open-source, it can be made available upon request. More
Developed a short-range DFT xc functional, (Python + Fortran + f2py). More
Developed a Python wrapper for the DIRAC program, which is used for high-precision quantum chemical calculations. The wrapper provides an easy-to-use interface for performing complex calculations and analyzing results. More
Developed PyGACE, a Python package combining genetic algorithms and cluster expansion method. More
Skills
SOFTWARE: Dalton, Gaussian, DIRAC, PySCF, PSI4, VASP, ATAT, LAMMPS, Pymatgen, Atomate, Horton
SCRIPTING: Python, Fortran, C++, C, Julia
Awards
2018: National Scholarship, Beihang University, Beijing, China
2016: Outstanding Graduates, Huazhong University of Science and Technology, Wuhan, China
2014: National Scholarship, Merit Student, Huazhong University of Science and Technology, Wuhan, China
2013: Merit Student, Excellent Student Cadre, Huazhong University of Science and Technology, Wuhan, China
2012: Excellent Student Cadre, Huazhong University of Science and Technology, Wuhan, China
References
Prof. Dr. Benjamin Stamm, University of Stuttgart, Stuttgart, Germany. benjamin.stamm@mathematik.uni-stuttgart.de
Prof. Dr. Toon Verstraelen, Ghent University, Ghent, Belgium. toon.verstraelen@ugent.be
Prof. Dr. Linggang Zhu, BUAA, Beijing, China. lgzhu7@buaa.edu.cn
Prof. Dr. Zhimei Sun, BUAA, Beijing, China. zmsun@buaa.edu.cn
Prof. Dr. Bin Shan, HUST, Wuhan, China. bshan@mail.hust.edu.cn