Tight-binding molecular dynamics structure calculations

Much of the theoretical effort to understand molecular structure at the metal-water interface is contained in the work of Halley [21,22,28,29,55]. A tight-binding molecular dynamics method was developed in which the electrons in the metal are treated via first principles calculations. The water phase was treated classically and coupled to the metal such that the electronic structure is matched at the metal water interface and the double-layer was appropriately accounted for. The structure and orientation of water at the interface and the nature of the potential drop were investigated [21,22,55]. The results agree with experimental observations of the extent of water orientation at the electrode lectrolyte interface [20]. 

Recent advances in first-principles molecular dynamics (MD) calculations, which follow the Newtonian dynamics of classically treated nuclei, have made electronic-structure calculations applicable to the study of large systems where previously only classical simulations were possible. Examples of quantum-mechanical (QM) simulation methods are Born-Oppenheimer molecular dynamics (BOMD), Car-Parrinello molecular dynamics (CPMD), tight-binding molecular dynamics (TBMD), atom-centered density matrix propagation molecular dynamics (ADMPMD), and wavepacket ab idtb molecular dynamics (WPAIMD). 

S. Goedecker and M. Teter Tight-binding electronic-structure calculations and tight-binding molecular dynamics with localized orbitals, Phys. Rev. R 51, 9455-9464 (1995). 

In summary, using tight-binding molecular dynamics simulations, we have demonstrated qu ilitative differences in the physical properties of carbon nanotubes and graphitic carbon. Furthermore, we have presented an efficient Green s function formalism for calculating the quantum conductance of SWCNs. Our work reveals that use of full orbital basis set is necessary for realistic ceilculations of quantum conductance of carbon nanotubes. Rirthermore, our approach allows us to use the same Hamiltonian to ceilculate quantum conductivity as well as to perform structural relaxation. 

Zhang and co-workers used this objective molecular-dynamics approach together with a density-functional tight-binding method to calculate the structural and electronic properties of M0S2 nanotubes of different diameters and chiralities. In order to characterize the objective... 

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