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Dr Qing Peng from Rensselaer Polytechnic Institute, USA visited BIT
【Close the window】author ：Baoqiao Guo Release time ：2015-09-25
Invited by prof Pengwan Chen, Dr Qing Peng from Rensselaer Polytechnic Institute, USA visited BIT and gave an oral talk entitled "
One parameter tuning exchange functional in density functional theory modeling of semi-hard materials”
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Shor Bio:
Qing Peng is a postdoctoral research associate in Department of Mechanical, Aerospace & Nuclear Engineering, Rensselaer Polytechnic Institute and an adjunct professor in School of power and mechanical engineering, Wuhan University. Dr. Peng serves as an Editorial board member for Scientific Reports.He received his Ph.D. in physics from University of Connecticut, M.S. from Binghamton University, and B.S. from Peking University. His research focuses on advanced materials mechanics using multiscale and first-principles computational modeling and simulation. He is the main developer of the QCDFT (Quasi-Continuum Density Functional Theory) method which allows full quantum simulation of materials at micron scales and beyond. With QCDFT, he and coworkers have successfully unveiled the strengthening mechanism of solid solution and hydrogen assisted cracking in aluminum. He also studied the nonlinear mechanical behaviors of two-dimensional materials, providing a safe-guide of their applications. In addition, he studied the mechanics coupling with radiation hardness in 2D materials, radiation damage in HCP metals, and pyroelectrics.
Abstract:
We assess the performance of van der Waals (vdW) density functionals in predicting the lattice parameters of β-cyclotetramethylene tetranitramine (HMX), a semi-hard molecular crystal. We propose a one-parameter empirical van der Waals density functional labelled as vdW-DF2k to continuously tune the lattice constants by adjusting the enhancement factor of the exchange energy functional. We find this method to be simple and robust over a wide tuning range when calibrating the functional on-demand with experimental data. With calibrated value k = 1.05, the proposed vdW-DF2k method shows good performance in predicting the geometries of 11 common energetic material molecular crystals and 3 typical layered van der Waals crystals, suggesting a wide use in modeling semi-hard materials.