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Workshop on HPC in India Chemical Dynamics in Aqueous Media Amalendu Chandra Department of Chemistry, Indian Institute of Technology Kanpur, India 208016.

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Presentation on theme: "Workshop on HPC in India Chemical Dynamics in Aqueous Media Amalendu Chandra Department of Chemistry, Indian Institute of Technology Kanpur, India 208016."— Presentation transcript:

1 Workshop on HPC in India Chemical Dynamics in Aqueous Media Amalendu Chandra Department of Chemistry, Indian Institute of Technology Kanpur, India ATIP 1 st Workshop on HPC in SC-09

2 A. ChandraATIP 1 st Workshop on HPC in SC-092 Hydrogen bonded (tetrahedral) structure of water

3 A. ChandraATIP 1 st Workshop on HPC in SC-093 Hydrogen bond fluctuations in water and aqueous solutions

4 A. ChandraATIP 1 st Workshop on HPC in SC-094 Excess proton in water

5 A. ChandraATIP 1 st Workshop on HPC in SC-095 Experimental Methods  X-ray and Neutron Scattering  Low frequency Raman ( < 200 cm -1 )  Time Resolved Infrared Spectroscopy Transient hole burning studies using IR laser

6 A. ChandraATIP 1 st Workshop on HPC in SC-096 Pump-probe signal at different delay times Variation of H-bond distance with time Relaxation time ~ 1.0 ps G.M.Gale etal PRL, 82, 1068 (1999) = ~ fs, ~ 1-2 ps A. Tokmakoff and coworkers JCP (2005) M.D. Fayer and coworkers, PNAS (2007)

7 A. ChandraATIP 1 st Workshop on HPC in SC-097 Computation of Aqueous Systems

8 A. ChandraATIP 1 st Workshop on HPC in SC-098 Ab initio Molecular Dynamics Forces are calculated from electronic structure calculation that are performed on-the-fly as the MD trajectory is generated. Car-Parrinello Method: R. Car and M. Parrinello, Phys. Rev. Lett., 55, 2471 (1985) J. Hutter et al. CPMD, MPI Stuttgart and IBM Zurich

9 A. ChandraATIP 1 st Workshop on HPC in SC-099 A.Chandra and coworkers, JPC/A (2008); JCP (2008) OH stretch frequency vs time in liquid water

10 A. ChandraATIP 1 st Workshop on HPC in SC-0910 Frequency vs hydrogen bond distance (pure D 2 O )

11 A. ChandraATIP 1 st Workshop on HPC in SC-0911 Dynamics of vibrational spectral diffusion: Hole creation and subsequent dynamics from nonequilibrium probability distributions Hole creation: Monte Carlo algorithm

12 A. ChandraATIP 1 st Workshop on HPC in SC-0912 Dynamics after hole creation: Excitation in blue/red Experiments: G.M. Gale et al PRL (1999)

13 A. ChandraATIP 1 st Workshop on HPC in SC-0913 Time dependence of average frequency after hole creation  1 ~ 100 fs (dynamics of intact hydrogen bonds)  2 ~ 2 ps (lifetimes of hydrogen bonds)  s ~ 100 cm -1 (intermolecular stretching/bending vibrations) A. Chandra and coworkers, JPC/A (2008); JCP (2009)

14 A. ChandraATIP 1 st Workshop on HPC in SC-0914 ScH 2 O Supercritical water 673K/ K/ K/ K/ A.K Soper et al., JCP, 106, 249 (1996)

15 A. ChandraATIP 1 st Workshop on HPC in SC-0915 Correlations between OD frequency and D..O distance A. Chandra and coworkers, JPC/A (2008)

16 A. ChandraATIP 1 st Workshop on HPC in SC-0916 Proton Transfer in water Eigen Zundel complex

17 A. ChandraATIP 1 st Workshop on HPC in SC-0917 Mobility of H 3 O + in liquid water D H 3 O + = 9.31x10 -5 cm 2 /s D H 2 O = 2.30x10 -5 cm 2 /s Mobility of OH - in liquid water D OH _ = 5.3x10 -5 cm 2 /s M.E. Tuckerman, D.Marx and M. Parrinello, Nature, 417, 925 (2002) A.Chandra, M. Tuckerman and D.Marx, PRL (2007); Acc. Chem. Res. (2006) Proton Migration Dynamics

18 A. ChandraATIP 1 st Workshop on HPC in SC-0918 Protonic defects in water clusters Where is the protonic defect located? Is there any proton transfer in clusters? A. Bankura and A. Chandra, JCP (submitted)

19 Describes chemically relevant part of large system using quantum mechanics (QM) and rest by molecular mechanics (MM) QM/MM Technique Long Range (LR) Short Range (SR) QM Density H 3 O + /OH - in different carbon nanotube systems Effects of confinement Quantum-classical simulations

20 A. ChandraATIP 1 st Workshop on HPC in SC-0920 Financial support: DST, CSIR, BRNS, MCIT (Government of India) AvH Foundation (Germany) Group members:

21 A. ChandraATIP 1 st Workshop on HPC in SC-0921 IIT Kanpur ….


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