Lessons learned during the war in Ukraine: a report from the Renal Disaster Relief Task Force of the ERA.

People living with kidney disease are among the most vulnerable at times of natural or man-made disasters. In addition to their unpredictable course, armed conflicts impose a major threat given the disruption of infrastructure, sanitation and access to food, water and medical care. The ongoing war in Ukraine has once more demonstrated the importance of preparedness, organization, coordination and solidarity during disasters.

Towards hybrid density functional calculations of molecular crystals via fragment-based methods.

We introduce and employ two QM:QM schemes (a quantum mechanical method embedded into another quantum mechanical method) and report their performance for the X23 set of molecular crystals. We furthermore present the theory to calculate the stress tensors necessary for the computation of optimized cell volumes of molecular crystals and compare all results to those obtained with various density functionals and more approximate methods. Our QM:QM calculations with PBE0:PBE+D3, PBE0:PBE+MBD, and B3LYP:BLYP+D3 yield at a reduced computational cost lattice energy errors close to the ones of the parent hybrid density functional method, whereas for cell volumes, the errors of the QM:QM scheme methods are in between the generalized gradient approximation and hybrid functionals.

Aptamer-facilitated mass cytometry.

Mass cytometry is a novel cell-by-cell analysis technique, which uses elemental tags instead of fluorophores. Sample cells undergo rapid ionization in inductively coupled plasma and the ionized elemental tags are then analyzed by means of time-of-flight mass spectrometry. Benefits of the mass cytometry approach are in no need for compensation, the high number of detection channels (up to 100) and low background noise.

Development of Embedded and Performance of Density Functional Methods for Molecular Crystals.

We report an alternative quantum mechanical:quantum mechanical (QM:QM) method to the currently used periodic density functional calculations including dispersion and investigate its performance with respect to main structural and energetic properties of the X23 set of molecular crystals. By setting the goal of reproducing reference periodic BLYP+D3 values and by embedding BLYP+D3 into DFTB, we obtain results similar to those of periodic BLYP+D3-typically within 1-2% in lattice energies and ∼0.4% in cell volumes.

Geometry-dependent atomic multipole models for the water molecule.

Models of atomic electric multipoles for the water molecule have been optimized in order to reproduce the electric potential around the molecule computed by ab initio calculations at the coupled cluster level of theory with up to noniterative triple excitations in an augmented triple-zeta quality basis set. Different models of increasing complexity, from atomic charges up to models containing atomic charges, dipoles, and quadrupoles, have been obtained. The geometry dependence of these atomic multipole models has been investigated by changing bond lengths and HOH angle to generate 125 molecular structures (reduced to 75 symmetry-unique ones).

Dipole and quadrupole polarizabilities of the water molecule as a function of geometry.

Dipolar, dipole-quadrupole and quadrupole-quadrupole static polarizabilities of the water molecule have been determined by ab initio calculations at coupled cluster level of theory with single, double and perturbative triple excitations CCSD(T) with an aug-cc-pVTZ basis set using a finite field and field-gradient method. The geometry dependence of polarizability tensor components has been explored and modeled by power series expansion in bond length and angle variations up to sum of powers equal to 4. The results provide a very detailed description of the static polarizability of water up to quadrupolar rank which can be used for the test and development of novel accurate polarizable interaction potentials for modeling aqueous solutions.

Geometry-dependent distributed polarizability models for the water molecule.

Geometry-dependent distributed polarizability models have been constructed by fits to ab initio calculations at the coupled cluster level of theory with up to noniterative triple excitations in an augmented triple-zeta quality basis set for the water molecule in the field of a point charge. The investigated models include (i) charge-flow polarizabilities between chemically bonded atoms, (ii) isotropic or anisotropic dipolar polarizabilities on oxygen atom or on all atoms, and (iii) combinations of models (i) and (ii). For each model, the polarizability parameters have been optimized to reproduce the induction energy of a water molecule polarized by a point charge successively occupying a grid of points surrounding the molecule.

Revealing water's secrets: deuterium depleted water.

Background: The anomalous properties of water have been of great interest for generations of scientists. However the impact of small amount of deuterium content which is always present in water has never been explored before. For the first time the fundamental properties of deuterium depleted (light) water at 4°C and 20°C are here presented.

Electronic and vibrational linear and nonlinear polarizabilities of Li@C60 and [Li@C60]+.

Electronic and vibrational nuclear relaxation (NR) contributions to the dipole (hyper)polarizabilities of the endohedral fullerene Li@C(60) and its monovalent cation [Li@C(60)](+) are calculated at the (U)B3LYP level. Many results are new, while others differ significantly from those reported previously using more approximate methods. The properties are compared with those of the corresponding hypothetical noninteracting systems with a valence electron transferred from Li to the cage.

Linear and nonlinear optical properties of triphenylamine-functionalized C60: insights from theory and experiment.

In the present study we report on the linear and nonlinear optical properties of C(60)-triphenylamine (TPhA) hybrids. The synthesized materials were prepared following the 1,3-dipolar cycloaddition of azomethine ylides onto the skeleton of C(60) forming the TPhA-based monoadduct, equatorial bis-adduct and dumbell C(60). Complementary spectroscopic techniques, such as NMR, MALDI-TOF-MS, and ATR-IR are applied for the structural characterization of the hybrid materials, while intermolecular electronic interactions are investigated by UV-Vis measurements.

Linear and nonlinear optical properties of [60]fullerene derivatives.

Using a wide variety of quantum-chemical methods we have analyzed in detail the linear and non-linear optical properties of [60]fullerene-chromophore dyads of different electron-donor character. The dyads are composed of [60]fullerene covalently linked with 2,1,3-benzothiadiazole and carbazole derivatives. Linear scaling calculations of molecular (hyper)polarizabilities were performed using wave function theory as well as density functional theory (DFT).

Isomerization of free base porphyrin. Theoretical study.

The photoinduced isomerization reaction of free base porphyrin molecule has been calculated using the DFT-B3LYP method combined with the 6-31G(d,p) basis set. To prove the accuracy of results, the 6-311G+(2p,2d) basis set was used. Two types of isomerization mechanisms were studied.

Physical properties and spectra of IO, IO- and HOI studied by ab initio methods.

Structure and properties of the IO, IO- and HOI species, which are of potential importance for the ozone destruction catalytic cycle in the troposphere, have been calculated together with the EPR, NMR and UV-visible spectra by ab initio methodology with account of spin-orbit coupling (SOC) effects. Multi-configuration self-consistent field calculations with linear and quadratic response techniques and the multi-reference configuration interaction method have been employed. Photodissociation of these species, crucial for the catalytic ozone-destruction cycle, is critically reviewed and analyzed.