Marie Backman, a physicist at the University of Helsinki, Finland, and coworkers have explored the mechanism behind bonding of gold atoms with other atoms using a model. This model takes bond direction into account.
The study results provide new insights into the bonding mechanism of gold atoms with other atoms through powerful covalent bonds. These results will be featured in EPJ B. Majority of earlier models were considered only interplays in the spherical electron density surrounding the atoms. Albeit it is ideal to describe gold-gold bonds, it is not sufficient to elucidate the bonding mechanism of surface gold atoms with other materials because the density of interplaying electrons is not spherical in such cases.
However, bond angles play an important role in the bonding of gold atoms with other atoms. Hence the researchers utilized a model built upon potentials with angular dependence called Tersoff potential. It offsets the inclusion of bond directionality, which is essential for covalent bonds, while maintaining the computational time required for the simulations low.
Using theoretical and computational analysis, the researchers studied the interaction of gold atoms with their neighbors. They fixed their potential functions to significant observed features of gold, including gold atom’s elastic constants, binding energy and lattice constant. These potential functions allowed the researchers to elucidate bonding in atomistic simulations. The new model involves the determination of forces on every atom on the basis of their corresponding positions followed by finding solutions to equations of motion to demonstrate the movement of atoms on a diminutive time scale.
Based on this new model, it is possible to develop cross potentials for gold nanorods and nanoparticles in a matrix, normally utilized in nanophotonics and biomedical imaging.
Source: http://www.springer.com