Bond-boost potential

The pairwise nature of the bond-boost makes this task easier since such traps would show up as a non-convexity of some of the biased effective pair potentials, which in the canonical ensemble can be taken to be the pairwise potential of mean force (PMF, denoted as V). Thus, assuming that V is approximately quadratic for lei safety condition can be enforced by setting Sa[Pg.92]

Similar in spirit is the method of conformational flooding, which is used to study and to predict large-scale conformational motions in maaomolecular systems on a microsecond timescale. In this approach, the bias (flooding) potential can be applied to one intramolecular energy term only (e.g., torsional terms) so as not to destroy solvent stmcture around the maciomolecule. The bias potential dynamics, the bond-boost method, and the state-bridging bond-boost method are also variants of Voter s hyperdynamics. 

The main difficulty, therefore, lies in the construction of a suitable and cheap bias potential. Fichthorn et al. [44] developed a so-called bond-boost method, in which the boost potential is derived from the concept of bond breaking events in a solid. Thus, the boost potential in this approach is a function of all nearest-neighbor bond lengths associated with the atoms of interest. Using this technique, these authors studied the diffusion of Cu adatoms, dimers and vacancies on a Cu(OOl) surface [44]. In these simulations, average boost factors in the range lO -lO were obtained in the temperature range 230-600 K. 

To the best of our knowledge, no Pt-based catalyst is able to promote the selective oxidation of ethanol to either CO2, acetic acid or acetaldehyde. However, the product composition can be modified by alloying Pt with other metals. For example, the addition of Sn to Pt increases the catalytic activity and also the production of acetic acid, while the addition of Ru improves the electrical performance without changing the product selectivity. Several authors have demonstrated that Ru and Sn are able to activate water al lower potential than pnre Pt, thus boosting the formation of CO2 and acetic acid, while Sn is particularly suited to reduce C-C bond breaking through a sort of dilution of adjacent Pt atoms. ... 

This reaction is an example of converting the potential energy contained in the hydrocarbon bonds to the kinetic energy of the hot gas molecules. The increeise in the number of gas molecules boosts the pressure tremendously, shoving the piston down. The linear motion is then converted to a rotary motion, which powers the wheels. And off you go ... 

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