First-principles prediction and partial characterization of the vibrational states of water up to dissociation

A new, accurate, global, mass-independent, first-principles potential energy surface (PES) is presented for the ground electronic state of the water molecule. The PES is based on 2200 energy points computed at the all-electron aug-cc-pCV6Z IC-MRCI(8,2) level of electronic structure theory and includes the relativistic one-electron mass-velocity and Darwin corrections. For H₂¹⁶O, the PES has a dissociation energy of D₀ = 41 109 cm⁻¹ and supports 1150 vibrational energy levels up to 41 083 cm⁻¹. The deviation between the computed and the experimentally measured energy levels is below 15 cm⁻¹ for all the states with energies less than 39 000 cm⁻¹. Characterization of approximate vibrational quantum numbers is performed using several techniques: energy decomposition, wave function plots, normal mode distribution, expectation values of the squares of internal coordinates, and perturbing the bending part of the PES. Vibrational normal mode labels, though often not physically meaningful, have been assigned to all the states below 26 500 cm⁻¹ and to many more above it, including some highly excited stretching states all the way to dissociation. Issues to do with calculating vibrational band intensities for the higher-lying states are discussed.     

Products of conjugacy classes in Chevalley groups I. Extended covering numbers

This paper is concerned with products of conjugacy classes in Chevalley groups. We prove that in any quasisimple Chevalley groupG proper or twisted, over any field, the extended covering number is bounded above linearly in terms of the rank ofG, that is, for some constante, for any Chevalley groupG, the product of anye · rank(G) non-central classes covers all ofG. We give estimates for the constante in different cases. The authors gratefully acknowledge the support of EPSRC through a Visiting Fellowship number GR/M58542 and a Research grant number GR/L92174.     

New supported beta-amino alcohols as efficient catalysts for the enantioselective addition of diethylzinc to benzaldehyde under flow conditions

[formula: see text] Polymeric monoliths 10 containing an amino alcohol moiety derived from an industrial waste material represent one of the best ligands for the enantioselective catalytic addition of ZnEt2 to benzaldehyde (99% ee), being recoverable and usable under flow conditions.     

Resolvent Tests for Similarity to a Normal Operator

The main result of this paper is the resolvent similarity criterionwhich says that linear growth of the resolvent towards the spectrumis sufficient for a Hilbert space contraction with finite rankdefect operators and spectrum not covering the unit disc tobe similar to a normal operator. Similar results are provedfor operators having a spectral set bounded by a Dini-smoothJordan curve; in particular, a dissipative operator with finiterank imaginary part is similar to a normal operator if and onlyif its resolvent grows linearly towards the spectrum. Relevantresults on the insufficiency of linear resolvent growth notaccompanied by smallness of defect operators are presented.Also it is proved that there is no restriction on the spectrum,other than finiteness, which together with linear resolventgrowth implies similarity to a normal operator. The constructionof corresponding examples depends on a characterization of well-knownAhlfors curves as curves of linear length growth with respectto linear fractional transformations. 1991 Mathematics SubjectClassification: 11D25, 11G05, 14G05.     

Unique description of chemical structures based on hierarchically ordered extended connectivities (HOC procedures). VIII. General principles for computer implementation

The computer implementation of the HOC procedures presented in Parts I, II and III of this series is based on the module principle. It contains a main program and seventeen subroutines in Fortran IV. The system is able to provide unique atom numbering and code for all kinds of chemical compounds in their tremendous variety of structures.     

Linear optics controlled-phase gate made simple

Linear optics quantum logic gates are the best tool to generate multiphoton entanglement. Simplifying a recent approach, we were able to implement the conditional phase gate with only one second-order interference at a polarization dependent beam splitter, thereby significantly increasing its stability. The improved quality of the gate is evaluated by analyzing its entangling capability and by performing full process tomography. The achieved results ensure that this device is well suited for implementation in various multiphoton quantum information protocols.     

Tuning intermolecular interactions in a rodlike polymer assembled at surfaces and in solution

The isolation of single polyelectrolyte chains of water-soluble poly(isocyanodipeptide)s (PICs) bearing carboxylic acid terminated side chains occurring both at surfaces and in solution was accomplished by reducing the intermolecular interactions through complexation with cations or positively charged surfactants.Scanning force microscopy and viscosity analyses revealed that this method allows to tune the conformation of the macromolecule, which is of importance for tailoring the physicochemical properties of the material.This is particularly significant for the use of these polymer chains as seed for biomineralization processes.