The mathematical representation of large data sets of electronic energies has seen substantial progress in the past 10 years. The so-called Permutationally Invariant Polynomial (PIP) representation is one established approach. This approach dates from 2003, ...

Medium and strong hydrogen bonds give rise to broad vibrational features frequently spanning several hundred wavenumbers and oftentimes exhibiting unusual substructures. These broad vibrational features can be modeled from first principles, in a reduced dimensional ...

A new paradigm for assigning vibrational spectra is described. Instead of proceeding from potential to Hamiltonian to eigenvalues/eigenvectors/intensities to spectrum, the new method goes “backwards'' directly from spectrum to eigenvectors. The eigenvectors then “assign'' the ...

Medium and strong hydrogen bonds give rise to vibrational features that can span several hundreds of wavenumbers and have unusual line shapes. For example, dimers consisting of carboxylic acids hydrogen-bonded to nitrogen-containing aromatic bases exhibit ...

Medium and strong hydrogen bonds are well known to give rise to broad features in the vibrational spectrum often spanning several hundred wavenumbers. In some cases, these features can span over 1000 cm−1 and even ...

Medium and strong hydrogen bonds are common in biological systems. Here, they provide structural support and can act as proton transfer relays to drive electron and/or energy transfer. Infrared spectroscopy is a sensitive probe of ...

A fluorescence lamp with wavelengths between 530-650 nm was used to activate two different isomers of substituted porphyrins (meso-tetra(N-methyl-2-pyridyl) and meso-tetra(N-methyl-3-pyridyl)). Each isomer was exposed to three different intensities (2.0, 4.5, and 8.0 W/m2) for ...

Light of particular wavelengths can activate some types of porphyrins more easily than others. In this project, we will use a fluorescence light to activate three different isomers of N-pyridyl mesosubstituted porphyrin using different intensities. ...

The detection limit for linear (fluorescence) and nonlinear (stimulated fluorescence or Raman) imaging can be improved by reducing noise. One way to reduce the noise in these types of imaging is to modulate the signal ...

The detection limit for linear (fluorescence) and nonlinear (stimulated fluorescence or Raman) imaging can be improved by reducing noise. One way to reduce the noise in these types of imaging is to modulate the signal ...