Category archives: Quantum chemistry

A new way to rationally design anti-Kasha emitters

A new way to rationally design anti-Kasha emitters

ChemistryDIPC Computational and Theoretical Chemistry

By DIPC

Light emission (fluorescence or phosphorescence) in organic molecules, in the vast majority of cases, proceeds from the lowest energy excited state irrespective of the excitation energy used. This is known as the Kasha’s rule, which states that most of the molecules are emissive from the lowest energy, same (ground state) spin multiplicity, S1 excited state […]

Dynamical nonlinear optical responses of organic materials

Dynamical nonlinear optical responses of organic materials

ChemistryDIPC Computational and Theoretical ChemistryMaterials

By DIPC

Nonlinear optics is concerned with the optical properties of matter subjected to intense electromagnetic fields. For nonlinearity to manifest itself, the external field should not be negligible compared to the internal fields of atoms and molecules of which the matter consists. Lasers are capable of generating external fields sufficiently intense for nonlinearity to occur. Actually […]

Donostia Natural Orbital Functional (DoNOF), an open-source program for quantum chemistry

Donostia Natural Orbital Functional (DoNOF), an open-source program for quantum chemistry

DIPC Computational and Theoretical Chemistry

By DIPC

Today, computational chemistry helps the experimental chemist understand experimental data, explore reaction mechanisms or predict completely new molecules. There is no doubt that understanding at the molecular level will ultimately lead to an ab initio process design. Thus, the solution of the quantum mechanical many-electron problem is one of the central problems of physics and […]

Remarkable enantiospecific response in Cross-Polarization Solid-State NMR experiments

Remarkable enantiospecific response in Cross-Polarization Solid-State NMR experiments

DIPC Computational and Theoretical Chemistry

By DIPC

If a nucleus has a non-zero spin, it behaves as a small magnet. Therefore, in an external magnetic field, the nuclear magnetic moment vector precesses about the field direction but only certain orientations are allowed by quantum rules. Thus, for hydrogen (spin 1/2) there are two possible states in the presence of a field, each […]

Magnetic Topological Quantum Chemistry, <i>ab initio</i> calculations included

Magnetic Topological Quantum Chemistry, ab initio calculations included

Condensed matterDIPC Advanced materialsMaterialsQuantum physics

By DIPC

Topological materials have special universal properties, which are protected against perturbations. Such properties are theoretically described by topology, a branch of mathematics concerned with the properties of geometrical objects that are unchanged by continuous deformations. Topological materials behave like an ordinary insulator in the bulk but have conducting states on their boundaries, i.e., edges or […]

Excited-state aromaticity

Excited-state aromaticity

ChemistryMaterials

By DIPC

We usually take for granted that aromaticity is something that belongs to the ground state of a molecule; but the fact is that nothing forbids aromaticity appearing in an excited state. In the same way that molecular properties are largely affected by the ground-state aromaticity, excited-state aromaticity can guide the understanding of excited-state processes, the […]

Mechanochemistry of nanographenes

Mechanochemistry of nanographenes

ChemistryCondensed matterMaterialsNanotechnology

By DIPC

Modern organic industrial chemistry started when William Henry Perkin serendipitously synthesized mauveine in 1856 while he was attempting the total synthesis of quinine. Since then, thousands of new organic products have been created in the laboratory for industrial purposes. Among them, in 1913, an orange-red pigment was found, first known as Vat Orange 3 dye […]

Submolecular resolution using inelastic electron tunnelling spectroscopy at 5 K

Submolecular resolution using inelastic electron tunnelling spectroscopy at 5 K

Condensed matterNanotechnologyQuantum physics

By DIPC

What only a decades ago seemed impossible for chemists, determining the chemical structure of molecules directly from experimental images, is now routinely done. Not only that, the information about bond order, intermediates, and products of on-surface chemical reactions or charge distribution within molecules can also be quantified from those images. Two main techniques have made […]