Beyond Born-Mayer: Improved Models for Short-Range Repulsion in ab Initio Force Fields

Short-range repulsion within intermolecular force fields is conventionally described by either Lennard-Jones (<i>A</i>/<i>r</i>¹²) or Born–Mayer (<i>A</i> exp­(−<i>Br</i>)) forms. Despite their widespread use, these simple functional forms are often unable to describe the interaction energy accurately over a broad range of intermolecular distances, thus creating challenges in the development of ab initio force fields and potentially leading to decreased accuracy and transferability. Herein, we derive a novel short-range functional form based on a simple Slater-like model of overlapping atomic densities and an iterated stockholder atom (ISA) partitioning of the molecular electron density. We demonstrate that this Slater–ISA methodology yields a more accurate, transferable, and robust description of the short-range interactions at minimal additional computational cost compared to standard Lennard-Jones or Born–Mayer approaches. Finally, we show how this methodology can be adapted to yield the standard Born–Mayer functional form while still retaining many of the advantages of the Slater-ISA approach

ЛЕЧЕНИЕ И ПРОФИЛАКТИКА АДЕНОИДИТОВ БАКТЕРИАЛЬНЫМИ ЛИЗАТАМИ У ЧАСТО БОЛЕЮЩИХ ДЕТЕЙ

We carried out the analysis of researches devoted to the treatment of children with chronic adenoiditis and hypertrophy of adenoid vegetations. We proved that the usage of topic immunomodulator IRS19 incombination with etiotropic treatment allows to sanate lymphoid tissues in nasopharynx effectively and to preserve its continuity as an important organ supplying unspecific and specific protection of the child’s organism.Проведен анализ исследований, посвященных лечению детей с хроническим аденоидитом и гипертрофией аденоидных вегетаций. Показано, что применение топического иммуномодулятора ИРС 19 в комплексе с этиотропным лечением позволяет более эффективно провести санацию лимфоидной ткани носоглотки и сохранить ее целостность как важного органа, обеспечивающего неспецифическую и специфическую защиту детского организма

Lattice distortion of quantum cryocrystals under pressure

The hcp lattice distortion parameter δ, the deviation of c/a ratio from the ideal hcp value √ 8/3 , have been calculated for solid He under pressure taking into account two- and three-body interatomic forces. The resulting lattice distortion parameter is small and negative, that is the lattice is slightly flattened compared with the ideal hcp lattice. It monotonically increases in absolute value with pressure and reaches 10⁻³ for molar volume of ~ 2.5 cm³/mol. Such small distrotions are most likely outside of possibilities of x-ray or neutron experiments but can be detected by optical methods based on measurements of the birefringence. The data on δ can be used as a probe of the many-body forces

TREATMENT AND PREVENTION OF ADENOIDITIS WITH BACTERIAL LYSATES IN SICKLY CHILDREN

We carried out the analysis of researches devoted to the treatment of children with chronic adenoiditis and hypertrophy of adenoid vegetations. We proved that the usage of topic immunomodulator IRS19 incombination with etiotropic treatment allows to sanate lymphoid tissues in nasopharynx effectively and to preserve its continuity as an important organ supplying unspecific and specific protection of the child’s organism