Geometry guided crystal phase transition pathway search

Geometry Guided Phase Transition Pathway and Stable Structure Search for Crystals

Stochastic surface walking method for crystal structure and phase transition pathway prediction.

The determination of crystal structures and the solid-to-solid phase transition mechanisms are two important and related subjects in material science. Here we develop an unbiased general-purpose potential energy surface (PES) searching method, namely, SSW-crystal method, for prediction of both the crystal structure and the crystal phase transition pathway. The SSW-crystal method features with s...

Investigation into the temperature dependence of isotropic- nematic phase transition of Gay- Berne liquid crystals

Density functional approach was used to study the isotropic- nematic (I-N) transition and calculate the values of freezing parameters of the Gay- Berne liquid crystal model. New direct and pair correlation functions of a molecular fluid with Gay- Berne pair potential were used. These new functions were used in density functional theory as input to calculate the isotropic- nematic transition den...

Structural phase transitions, and Br.N and Br.Br interactions in 1-phenyl-2-methyl-4-nitro-5-bromoimidazole.

Crystals of C(10)H(8)N(3)O(2)Br undergo two reversible phase transitions between 295 and 100 K. The first, of an order-disorder nature, is a second-order transition and takes place continuously over a wide temperature range. This transition is connected with the doubling of the length of the c axis of the unit cell and with the change of the space group from P2(1)/m with Z' = 1/2 (room-temperat...

Minima hopping guided path search: an efficient method for finding complex chemical reaction pathways.

The Minima Hopping global optimization method uses physically realizable molecular dynamics moves in combination with an energy feedback that guarantees the escape from any potential energy funnel. For the purpose of finding reaction pathways, we argue that Minima Hopping is particularly suitable as a guide through the potential energy landscape and as a generator for pairs of minima that can b...