Abstract

In order to study the effect of the quantization of vibrations on structural and dynamical properties of solids, I will present a general methodology based on mapping a suitable subspace of the vibrational manifold and solving the Schroedinger equation in it. I will describe a number of increasingly accurate approximations, and analyse in detail results for a model monoatomic chain and a hydrogen-bonded diatomic chain.Next, I will present two realistic case studies, where the potential is obtained from first-principles calculations at the DFT level: 1) a hydrogen-bonded H-F chain, and 2) the zero-dimensional H-bonded compound CrOOH. The focus is placed specifically on quantum nuclear effects on lattice constants and interatomic parameters.

References:

[1] Basics of phonons: C. Kittel, Introduction to Solid States Physics, 8th ed. (Wiley, NY, 2005), chapters 4 and 5.

[2] Anharmonic effects: G. Liebfried and W. Ludwig in Solid State Physics, Ed. Seitz and Turnbull, vol 12 (Academic, New York, 1961); L. N. Kantorovich, Phys. Rev. B 51 , 3520 (1995).

[3] VSCF method: M. A. Ratner and R. B. Gerber, J. Phys. Chem. 90, 20(1986)

[4] This work: I. Scivetti, D. Hughes, N. I. Gidopoulos, A. Caro, and J. Kohanoff, AIP Conference Proceedings 963, 212 (2007); I. Scivetti, N. I. Gidopoulos and J. Kohanoff, Phys. Rev. B (submitted