Constrained molecular dynamics in the isothermal-isobaric ensemble and its adaptation for adiabatic free energy dynamics

Autor: Tang Qing Yu, Mark E. Tuckerman
Rok vydání: 2011
Předmět:
Zdroj: The European Physical Journal Special Topics. 200:183-209
ISSN: 1951-6401
1951-6355
DOI: 10.1140/epjst/e2011-01524-x
Popis: The implementation of holonomic constraints within measure-preserving integrators for molecular dynamics simulations in the isothermal-isobaric ensemble is considered. We review the basic methodology of generating measure-preserving integrators for the microcanonical, canonical, and isothermal-isobaric ensembles and proceed to show how the standard SHAKE and RATTLE algorithms must be modified for the isothermal-isobaric ensemble. Comparison is made between constrained and unconstrained simulations employing multiple time scale integration techniques. Finally, we describe a temperature accelerated version of the isothermal-isobaric molecular dynamics approach, in which the cell matrix is adiabatically decoupled from the particles and maintained at a high temperature as a means of exploring polymorphism in molecular crystals. We demonstrate that constraints can be easily adapted for this new approach and, again, we compare the performace of this temperature-accelerated scheme with and without bond constraints.
Databáze: OpenAIRE
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