Pressure-Induced Frustration and Disorder in <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Mg</mi><mo>(</mo><mi>OH</mi><mrow><msub><mrow><mo>)</mo></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> and <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Ca</mi><mo>(</mo><mi>OH</mi><mrow><msub><mrow><mo>)</mo></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span>

Simone Raugei; Pier Luigi Silvestrelli; Michele Parrinello

doi:10.1103/PhysRevLett.83.2222

Pressure-Induced Frustration and Disorder in $Mg (OH)_{2}$ and $Ca (OH)_{2}$

Simone Raugei, Pier Luigi Silvestrelli, and Michele Parrinello

Phys. Rev. Lett. 83, 2222 – Published 13 September 1999

Abstract

Using ab initio molecular dynamics we study pressure-induced hydrogen sublattice amorphization in $Mg (OH)_{2}$ and $Ca (OH)_{2}$ . Our calculations reproduce the experimental behavior of these two systems, with $Ca (OH)_{2}$ showing significantly more marked effects. We find that the interplay of short-range repulsion and electrostatic forces explains the amorphization process. This is due to a frustration phenomenon and has a dynamical character at room temperature, but it can be frozen in at low temperatures.

Received 12 August 1998

DOI:https://doi.org/10.1103/PhysRevLett.83.2222

Authors & Affiliations

Simone Raugei^1,2, Pier Luigi Silvestrelli¹, and Michele Parrinello¹

¹Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
²Laboratorio di Spettroscopia Molecolare, Dipartimento di Chimica, Via Gino Capponi 9, 50121 Firenze, Italy