Prof. Jian Sun [from Nanjing University, China]

Title: Probe new crystal structures using static and dynamical simulations

Time: 16:00 - 17:00, February 10
Place: Conference room 201, Building 6, HPSTAR (Shanghai)

Abstract:
Predicting the structures of crystal is important and relevant to all areas of science in which one would like to know the relative positions of atoms. Because the number of minima in the potential energy surface (PES) of a large system increase exponentially with the number of atoms, thus finding the most stable structure of such system is very difficult. Recently, based on the development of accurate theoretical approaches for calculating energies of assemblies of atoms and computing power, together with the progress in searching methodologies, numerous successful predictions have been obtained. In this talk, I will introduce some of our recent work on crystal structure predictions using a static approach, ab initio random structure searching (AIRSS) and dynamical method called ab initio metadynamics.

    References
    [1] J. Sun, M. Martinez-Canales, D. D. Klug, C. J. Pickard, R. J. Needs, Phys. Rev. Lett. 111, 175502 (2013).
     [2] J. Sun, Miguel Martinez-Canales, D.D. Klug, C.J. Pickard, and R.J. Needs, Phys. Rev. Lett. 108, 045503 (2012).
     [3] J. Sun, D.D. Klug, C.J. Pickard, and R.J. Needs, Phys. Rev. Lett. 106, 145502 (2011).
     [4] J. Sun, D.D. Klug and R. Martoňák, J. Chem. Phys. 130, 194512 (2009).
     [5] J. Sun, D.D. Klug, R. Martoňák, J. A. Montoya, M.-S. Lee, S. Scandolo, E. Tosatti, Proc. Natl. Acad. Sci. U.S.A. 106, 6077 (2009).
     [6] Y. Yao, DD Klug, J. Sun, R. Martonak, Phys. Rev. Lett. 103, 055503 (2009)  


Biography of the Speaker:

Prof. Sun's research interest is mainly in computational materials sciences by ab initio (or so-called firstprinciples) calculations and molecular dynamics simulations based on density functional theory. He has been involved in some projects spread in several aspects:

 * Polymerization of molecular crystals under high pressure, e.g. N2, O2, CO, CO2, etc.

 * High pressure phase transitions of semiconductors and metallic systems using metadynamics, e.g. Carbon, GaN, Calcium, etc.

 * Structure predictions for crystals with Random Search or Genetic algorithm.

 * Structural, lattice dynamics and optical properties of semiconductors.

 * Hardness of covalent materials, especially B-C-N system.

 * Hydrogen-bonding and solvation dynamics of aqueous solutions by ab initio molecular dynamics simulations.

 * Terahertz vibrational spectroscopy of liquids, e.g. water and bio-molecule solutions, especially amino acids solutions from ab initio simulations.