Vibrational free energy and phase stability of paramagnetic and antiferromagnetic CrN from ab initio molecular dynamics

Development of molecular dynamics methodology for simulations of hard materials

This thesis is focused on molecular dynamics simulations, both classical and ab initio. It is devoted to development of new methods and applications of molecular dynamics based techniques to a series of materials, all of which have the common property of being hard. I first study grain boundaries in diamond and apply a novel method to better explore the configurational phase space. Using this m...

Equation of state of paramagnetic CrN from ab initio molecular dynamics

Theoretical Description of the Electron-lattice Interaction in Molecular and Magnetic Crystals

Electron-lattice interactions are often considered not to play a major role in material’s properties as they are assumed to be small, the second-order effects. This study, however, shows the importance of taking these effects into account in the simulations. My results demonstrate the impact of the electron-lattice interaction on the physics of the material and our understanding from it. One wa...

Ab initio study , Investigation of NMR ShieldingTensors and Vibrational frequency of 5-S-cysteinyldopamine

The interaction of dopamine and cysteine for formation of 5-S-cysteinyldopamine are investigated at theHartree-Fock level theory. The structural and vibrational properties of 5-S-cysteinyldopamine are studiedat level of HF/6-31G*.Interaction energy ( AE) is calculated -771.6923 Kcal/mol Rotational energy andthermodynamic parameters around two bond have been determined using HF/3-21G. Changes of...

"Pump-probe" atom-centered density matrix propagation studies to gauge anharmonicity and energy repartitioning in atmospheric reactive adducts: case study of the OH + isoprene and OH + butadiene reaction intermediates.

Time-resolved "pump-probe" ab initio molecular dynamics studies are constructed to probe the stability of reaction intermediates, the mechanism of energy transfer, and energy repartitioning, for moieties involved during the interaction of volatile organic compunds with hydroxyl radical. These systems are of prime importance in the atmosphere. Specifically, the stability of reaction intermediate...