Order-disorder phase transition and dissociation of hydrogen sulfide under high pressure: Ab initio molecular dynamics study

This paper reports on the first ab initio molecular dynamics study of the ferroelectric Sodium Nitrite, shedding light on its order-disorder phase transition. The remnant polarization Pr was calculated using a Mulliken population analysis and maximally localized Wannier functions. Especially the Wannier based model is in excellent agreement with experimental findings and previous Berry phase calculations. The simulations predict a ferroelectric Curie temperature Tc between 400 K and 450 K in good agreement with the experimental value of 437 K. In addition, the anomalous lattice behavior (shrinking of the c-axis) during the phase transition is reproduced. The crystal field effect in the material could be quantified by investigating the molecular dipoles based on the maximally localized Wannier functions and the intermolecular charge transfer by analysing the Mulliken charges. In agreement with earlier experimental and theoretical findings, the polarization reversal mechanism was found to be dominated by a c-axis rotation of the Nitrite ions. The molecular insight into such a simple and prototypical material serves as a basis for a further development of more complex crystalline order-disorder ferroelectrics.

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Phase transition of GeO2 crystal at high pressure: An ab initio molecular dynamics study

International Journal of Chemistry and Technology ◽

10.32571/ijct.725601 ◽

2020 ◽

Vol 4 (1) ◽

pp. 90-96

Author(s):

Sebahaddin ALPTEKİN

Keyword(s):

Phase Transition ◽

Molecular Dynamics ◽

High Pressure ◽

Ab Initio ◽

Ab Initio Molecular Dynamics

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Lithium Hydroxide Phase Transition under High Pressure: An Ab Initio Molecular Dynamics Study

ChemPhysChem ◽

10.1002/cphc.200500272 ◽

2006 ◽

Vol 7 (1) ◽

pp. 141-147 ◽

Cited By ~ 16

Author(s):

Marco Pagliai ◽

Marcella Iannuzzi ◽

Gianni Cardini ◽

Michele Parrinello ◽

Vincenzo Schettino

Keyword(s):

Phase Transition ◽

Molecular Dynamics ◽

High Pressure ◽

Ab Initio ◽

Lithium Hydroxide ◽

Ab Initio Molecular Dynamics ◽

Hydroxide Phase

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Ab Initio Molecular Dynamics Simulations of the Ferroelectric-Paraelectric Phase Transition in Sodium Nitrite

10.26434/chemrxiv.7718633.v1 ◽

2019 ◽

Author(s):

Johannes P. Dürholt ◽

Rochus Schmid

Keyword(s):

Phase Transition ◽

Molecular Dynamics ◽

Ab Initio ◽

Sodium Nitrite ◽

Berry Phase ◽

Population Analysis ◽

Ab Initio Molecular Dynamics ◽

Mulliken Population ◽

Wannier Functions ◽

Disorder Phase Transition

This paper reports on the first ab initio molecular dynamics study of the ferroelectric Sodium Nitrite, shedding light on its order-disorder phase transition. The remnant polarization Pr was calculated using a Mulliken population analysis and maximally localized Wannier functions. Especially the Wannier based model is in excellent agreement with experimental findings and previous Berry phase calculations. The simulations predict a ferroelectric Curie temperature Tc between 400 K and 450 K in good agreement with the experimental value of 437 K. In addition, the anomalous lattice behavior (shrinking of the c-axis) during the phase transition is reproduced. The crystal field effect in the material could be quantified by investigating the molecular dipoles based on the maximally localized Wannier functions and the intermolecular charge transfer by analysing the Mulliken charges. In agreement with earlier experimental and theoretical findings, the polarization reversal mechanism was found to be dominated by a c-axis rotation of the Nitrite ions. The molecular insight into such a simple and prototypical material serves as a basis for a further development of more complex crystalline order-disorder ferroelectrics.

Download Full-text