TY  - JOUR
AU  - Wagner, Christian
AU  - Fournier, Norman
AU  - Ruiz, Victor G.
AU  - Li, Chen
AU  - Müllen, Klaus
AU  - Rohlfing, Michael
AU  - Tkatchenko, Alexandre
AU  - Temirov, Ruslan
AU  - Tautz, Frank Stefan
TI  - Non-additivity of molecule-surface van der Waals potentials from force measurements
JO  - Nature Communications
VL  - 5
SN  - 2041-1723
CY  - London
PB  - Nature Publishing Group
M1  - FZJ-2015-03347
SP  - 5568
PY  - 2014
AB  - Van der Waals (vdW) forces act ubiquitously in condensed matter. Despite being weak on an atomic level, they substantially influence molecular and biological systems due to their long range and system-size scaling. The difficulty to isolate and measure vdW forces on a single-molecule level causes our present understanding to be strongly theory based. Here we show measurements of the attractive potential between differently sized organic molecules and a metal surface using an atomic force microscope. Our choice of molecules and the large molecule-surface separation cause this attraction to be purely of vdW type. The experiment allows testing the asymptotic vdW force law and its validity range. We find a superlinear growth of the vdW attraction with molecular size, originating from the increased deconfinement of electrons in the molecules. Because such non-additive vdW contributions are not accounted for in most first-principles or empirical calculations, we suggest further development in that direction.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000345914100003
C6  - pmid:25424490
DO  - DOI:10.1038/ncomms6568
UR  - https://juser.fz-juelich.de/record/201037
ER  -