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Yusuf Hamied Department of Chemistry

 
 

A quantum mechanical description of nuclei, rather than a typical classical one, is required to obtain quantitative accuracy of the time-dependent properties of a molecular system. Our group’s work focuses on the combination of quantum statistics with classical dynamics via Feynman’s path-integral framework. We investigate the underlying theory of quantum statistics-classical dynamics methods and formulate new methods based on novel approximations. Recent successes in the group include the development of ‘Matsubara dynamics’ [1], in which minimal approximations are made to recover quantum-Boltzmann conserving classical dynamics and serves as the underlying framework of the popular Ring Polymer Molecular Dynamics (RPMD) and Centroid Molecular Dynamics (CMD) methods. More recently, a new method has emerged called Quasicentroid Molecular Dynamics (QCMD) [2], that is formulated in curvilinear space, thereby removing some of the computational artefacts found in RPMD and CMD.

My PhD work focuses on theoretical and methodological development of QCMD. Unlike the other methods, QCMD does not naturally generalise to arbitrary molecules and doing so is difficult. However, the reason for wanting to do so is clear; QCMD is the superior path-integral method for generating IR spectra, as demonstrated with calculations on condensed phase water and ice. In a recent publication, we successfully extended QCMD to ammonia-like geometries, again showing that it produces superior IR spectra across a range of temperatures [3].

Prior to joing the Althorpe group, I completed an MPhil in Scientific Computing at the CSC  and I am currently a member of the Computational Methods in Material Science CDT.

 

1. T. J. H. Hele, M. J. Willatt, A. Muolo, and S. C. Althorpe, J. Chem. Phys. 142, 134103 (2015).

2. G. Trenins, M. J. Willatt, and S. C. Althorpe, J. Chem. Phys. 151, 054109 (2019).

3. C. Haggard, V. Sadhasivam, G. Trenins and S. Althorpe, J. Chem. Phys. 155, 174120 (2021).

Publications

Improved torque estimator for condensed-phase quasicentroid molecular dynamics
G Trenins, C Haggard, SC Althorpe
– The Journal of Chemical Physics
(2022)
157,
174108
Testing the quasicentroid molecular dynamics method on gas-phase ammonia
C Haggard, VG Sadhasivam, G Trenins, SC Althorpe
– The Journal of Chemical Physics
(2021)
155,
174120

Research Group

Telephone number

01223 336353 (shared)

Email address

ch850@cam.ac.uk

College

Trinity Hall