All Outputs (1488)

Symmetry properties of one- and two- electron molecular integrals (1971)
Journal Article

The maximum numbers of distinct one- and two-electron integrals that arise in calculating the electronic energy of a molecule are discussed. It is shown that these may be calculated easily using the character table of the symmetry group of the set of... Read More about Symmetry properties of one- and two- electron molecular integrals.

Electric field strengths and ion trajectories in sharp-edge field ionization sources (1970)
Journal Article

On the presumption that a sharp edge may be represented by a hyperbola, a conformal transformation method is used to derive electric field equations for a sharp edge suspended above a flat plate. A further transformation is then introduced to give el... Read More about Electric field strengths and ion trajectories in sharp-edge field ionization sources.

Calculated ionization potentials of the linear alkanes (1970)
Journal Article

The equivalent orbital (EO) method is investigated and used for predicting outer and inner ionization potentials of the linear alkanes. The calculated ionization potentials are in good agreement with those observed in photoelectron spectra provided t... Read More about Calculated ionization potentials of the linear alkanes.

Calculation of electric field strengths at a sharp edge (1968)
Journal Article

Sharp edges were first used for field ionisation mass spectrometry by Beckey. Although Cross and Robertson found that etched metal foils were more effective than razor blades for field ionisation, blades are very convenient for determination of field... Read More about Calculation of electric field strengths at a sharp edge.

Structural optimization of molecular clusters with density functional theory combined with basin hopping
Journal Article

Identifying the energy minima of molecular clusters is a challenging problem. Traditionally, search algorithms such as simulated annealing, genetic algorithms, or basin hopping are usually used in conjunction with empirical force fields. We have impl... Read More about Structural optimization of molecular clusters with density functional theory combined with basin hopping.

Measuring proton shift tensors with ultrafast MAS NMR
Journal Article

A new proton anisotropic-isotropic shift correlation experiment is described which operates with ultrafast MAS, resulting in good resolution of isotropic proton shifts in the detection dimension. The new experiment makes use of a recoupling sequence... Read More about Measuring proton shift tensors with ultrafast MAS NMR.

A generic ?* shape resonance observed in energy-dependent photoelectron angular distributions from two-colour, resonant multiphoton ionization of difluorobenzene isomers
Journal Article

We present new evidence for the existence of a near threshold ?* shape resonance as a common feature in the photoionization of each isomer of difluorobenzene. Experimentally this is revealed by significant changes in the anisotropy of the photoelectr... Read More about A generic ?* shape resonance observed in energy-dependent photoelectron angular distributions from two-colour, resonant multiphoton ionization of difluorobenzene isomers.

Organic thermoelectric materials: new opportunities
Journal Article