Glass-formers and structure-seekers: From interatomic forces and potential-surface topographies to crystallization and protein folding

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:447612

Berry, R S; Astakhova, T; Ball, K D ^[1]

---

1. Univ. of Chicago, IL (United States); and others

The salient information for characterizing topographies of many-dimensional potential surfaces is the nature and distribution of the sequences of stationary points connecting the basin bottoms with the high reaches of the landscape. Roughly, the longer the range of the interatomic forces, the smoother is the topography. Landscapes studied thus far seem to fall into two classes: sawtooth-like, in which the changes in energy from one minimum to the next along a sequence of local minima monotonic in energy are small relative to the heights of the saddles separating successive minima, and staircase-like, in which some large changes in potential energy occur along monotonic sequences of minima, large compared with the heights of saddles linking those minima or others close to them. Sawtooth potentials appear to be associated with growth of nuclei by few-particle steps, and with glass formation. Staircase potentials seem to be associated with growth of nuclei by highly cooperative processes, and with {open_quotes}structure-seeking{close_quotes}--either crystallization or folding, in the case of a polymer model. The dynamics on the surface can be modeled reliably by a master equation based on thermal equilibration of the vibrational motion after entry into each new well, even for staircase potentials.

• OSTI ID: 447612
• Report Number(s): CONF-960343--
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
66 PHYSICS
CRYSTALLIZATION
GLASS
INTERATOMIC FORCES
POLYMERS
POTENTIAL ENERGY
PROTEINS
TOPOGRAPHY
VIBRATIONAL STATES