121st General Meeting of the KCS

Type Poster Presentation
Area Physical Chemistry
Room No. Event Hall
Time 4월 20일 (금요일) 11:00~12:30
Code PHYS.P-92
Subject Free energy level correction using Monte Carlo resampling approach with weighted histogram analysis method
Authors Seyoung Chung, Young Min Rhee1,*
Department of Chemistry, Pohang University of Science and Technology, Korea
1Department of Chemistry, Korea Advanced Institute of Science and Technology, Korea
Abstract Free energy calculations may provide vital information for studying various chemical and biological processes. Quantum mechanical methods are required to accurately describe the phenomena, but it is often too demanding for configurational sampling. As a remedy, level correction schemes that allow high level free energies to be calculated from configuration samples from lower level simulations have been developed. Here, we present two correction schemes, weighted histogram analysis method (WHAM) based dual level correction and Monte Carlo (MC) resampling with WHAM. We applied these two schemes for handling a simple toy model and for characterizing torsional dynamics of alanine dipeptide. The simple model showed that two approaches display potential of mean forces (PMFs) that converge to the exact one when an enough number of configurations were sampled. With a reduced sampling size, surface irregularities developed as expected and MC resampled WHAM displayed smoother morphology. Similar features were observed with the simulation of alanine dipeptide. From the MC resampled WHAM, we introduced a heuristic criteria for deciding the degree of additional smoothing on the free energy surface.
E-mail seyoung92@postech.ac.kr