Welcome

Originally from Hangzhou, China, I did my B.S. and M.S. in Chemical Engineering at UCLA. Currently I am a 4th year Ph.D. candidate (degree expected July 2023) in Prof. Philippe Sautet’s group at UCLA. My research focuses on using computational chemistry to understand surface processes, typically those used in semiconductor manufacturing processes. I am interested in developing accurate, efficient, and scalable simulation methods to probe the fabrication processes with atomistic resolution....

During chemistry work I often encounter problems with intensive computation where I need parallelize some intensive calculations. Here I list the typical problem cases and the strategies I used to solve them: Processing a big MD trajectory. In this case, a big MD trajectory file (e.g. LAMMPS dump) needs to be processed frame-by-frame to extract information. This file is too big to fit in the memory. Each frame in the trajectory consists of tens of thousands of atoms is therefore intensive to process....

Journals Articles Yantao Xia and Philippe Sautet, Thermodynamics of Atomic Layer Etching Chemistry on Copper and Nickel Surfaces from First Principles, Chemistry of Materials, 33, 17, 6774-6786 (2021) Yantao Xia, Thermodynamic Screening of Reaction Chemistries for Atomic Layer Etching of Metals, UCLA, 2020 Xia Sang, Yantao Xia, Jane P. Chang, and Philippe Sautet Directional and selective patterning of EUV absorbers, Proc. SPIE 11615, Advanced Etch Technology and Process Integration for Nanopatterning X, 1161503 (2021) Xia Sang, Yantao Xia, Philippe Sautet, and Jane P....

This is my notes when refreshing up on pCOHP theory. Emphasis is on intuition rather than rigor. DFT in periodic boundary conditions In periodic DFT, we calculate the non-interacting one-particle states that give the same electron density as the fully interacting states. This yields the one-electron bands and the band energies: \(\hat{H}\psi_j(\vec{k}, \vec{r}) = \epsilon_j(\vec{k})\psi_j(\vec{k}, \vec{r})\) The density of states is the number of allowed states between energies \(E\) and \(E+\delta E\):...