Van der Waals (vdW) interactions are ubiquitous in nature, playing a major role in defining the structure, stability, and function for a wide variety of molecules and materials. VdW interactions between atoms are weak (typically 0.01-0.1 eV), however the vdW energy scales linearly with system size and renders a large contribution to intermolecular and conformational energies. I will review the state-of-the-art of theoretical methods for the description of vdW interactions, ranging from empirical treatment in force fields to accurate ab initio calculations. Our recent developments for including the full long-range treatment of vdW energy accurately and efficiently will be presented [1,2,3,4]. Finally, I will show that vdW interactions are crucial for shaping the secondary structure of peptides and proteins, explaining the extreme thermal stability of polyalanine helices in vacuo [5].
[1] A. Tkatchenko and M. Scheffler, Phys. Rev. Lett. 102, 073005 (2009).
[2] A. Tkatchenko, R. A. DiStasio, Jr., M. Head-Gordon, M. Scheffler, J.
Chem. Phys. 131, 094106 (2009).
[3] X. Ren, A. Tkatchenko, P. Rinke, M. Scheffler, Phys. Rev. Lett. 106, in print (2011).
[4] A. Tkatchenko, R. A. DiStasio, Jr., R. Car, M. Scheffler, in preparation.
[5] A. Tkatchenko, M. Rossi, V. Blum, J. Ireta, M. Scheffler, Phys. Rev.
Lett. 106, 118102 (2011).