Fritz Haber Institute of the Max Planck Society

About: Fritz Haber Institute of the Max Planck Society is a facility organization based out in Berlin, Germany. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 3490 authors who have published 5017 publications receiving 183731 citations. The organization is also known as: Fritz Haber Institute of the Max Planck Society.

Fine Structure of the Infrared Absorption and Emission Spectra of Cu 2+ in ZnS and CdS Crystals

Abstract: Near-infrared absorption and emission spectra of ${\mathrm{Cu}}^{2+}$ as a substitutional impurity in ZnS and CdS crystals recorded at low temperatures are found to exhibit a pronounced fine structure. The optical transitions occur between energy levels which result from a splitting of the ${\mathrm{Cu}}^{2+}$ ground state by a crystal field of tetrahedral symmetry and the spin-orbit interaction. A small contribution of lower symmetry---possibly produced by Jahn-Teller effect---and an interaction of the center with vibration modes of the host lattice account for the occurrence of numerous lines. Crystal field and spin-orbit parameters were calculated for ${\mathrm{Cu}}^{2+}$ in ZnS and CdS crystals.

Structure determination of neutral MgO clusters--hexagonal nanotubes and cages.

Abstract: Structural information for neutral magnesium oxide clusters has been obtained by a comparison of their experimental vibrational spectra with predictions from theory. (MgO)n clusters with n = 3–16 have been studied in the gas phase with a tunable IR-UV two-color ionization scheme and size-selective infrared spectra have been measured. These IR spectra are compared to the calculated spectra of the global minimum structures predicted by a hybrid ab initio genetic algorithm. The comparison shows clear evidence that clusters of the composition (MgO)3k (k = 1–5) form hexagonal tubes, which confirm previous theoretical predictions. For the intermediate sizes (n a 3k) cage-like structures containing hexagonal (MgO)3 rings are identified. Except for the cubic (MgO)4 no evidence for bulk like structures is found.

Ultrafast vibrational energy transfer between surface and bulk water at the air-water interface

Abstract: (Received 11 September 2006; published 1 March 2007)We report a femtosecond time-resolved study of water at the neat water-air interface. The O-H stretchvibrational lifetime of hydrogen-bonded interfacial water is measured using surface-specific 4th-ordernonlinear optical spectroscopy with femtosecond infrared pulses. The vibrational lifetime in the frequencyrange of 3200 to 3500cm

Density functional theory study of the cooperativity of hydrogen bonds in finite and infinite α-helices

Abstract: We studied the energetics of finite and infinite polyalanine chains in the α-helical and extended structure by employing density-functional theory. On the basis of these results we extracted the energy of hydrogen bonds (hb's) and their interactions by taking the full peptide−peptide connectivity (backbone) of proteins into account. We focus on two limiting cases: an isolated hb and one within an infinite α-helical chain. In the infinite chain the cooperativity within an infinite network of hb's strengthens each individual bond by more than a factor of 2. This effect has important consequences for the stability of α-helices.