A generalized solid-state nudged elastic band method
Abstract
A generalized solid-state nudged elastic band (G-SSNEB) method is presented for determining reaction pathways of solid-solid transformations involving both atomic and unit-cell degrees of freedom. We combine atomic and cell degrees of freedom into a unified description of the crystal structure so that calculated reaction paths are insensitive to the choice of periodic cell. For the rock-salt to wurtzite transition in CdSe, we demonstrate that the method is robust for mechanisms dominated either by atomic motion or by unit-cell deformation; notably, the lowest-energy transition mechanism found by our G-SSNEB changes with cell size from a concerted transformation of the cell coordinates in small cells to a nucleation event in large cells. The method is efficient and can be applied to systems in which the force and stress tensor are calculated using density functional theory.
- Publication:
-
Journal of Chemical Physics
- Pub Date:
- February 2012
- DOI:
- 10.1063/1.3684549
- Bibcode:
- 2012JChPh.136g4103S
- Keywords:
-
- cadmium compounds;
- crystal structure;
- deformation;
- density functional theory;
- elasticity;
- II-VI semiconductors;
- nucleation;
- solid-state phase transformations;
- wide band gap semiconductors;
- 64.70.K-;
- 81.30.Hd;
- 64.60.Q-;
- 62.20.D-;
- 81.40.Jj;
- 61.66.Fn;
- Solid-solid transitions;
- Constant-composition solid-solid phase transformations: polymorphic massive and order-disorder;
- Nucleation;
- Elasticity;
- Elasticity and anelasticity stress-strain relations;
- Inorganic compounds