PubMed Health⌕ Search

Biomedical subjects

S A Bonev

Publications and source records attributed to S A Bonev.

2 recordsLinked to original sources
PubMed2003

High-pressure molecular phases of solid carbon dioxide.

We present a theoretical study of solid CO2 up to 50 GPa and 1500 K using first-principles calculations. In this pressure-temperature range, interpretations of recent experiments have suggested the existence of CO2 phases which are intermediate between molecular and covalent-bonded solids. We reexamine the concept of intermediate phases in the CO2 phase diagram and propose instead molecular structures, which provide an excellent agreement with measurements.

Journal Article↗
PubMed2003

Enhanced Friedel structure and proton pairing in dense solid hydrogen.

The mechanism of proton pairing in dense solid hydrogen, and its progression with density, are both studied using effective potentials between protons which include electronic response up to quadratic terms. For high pressures nonlinear effects originating with different pairs are crucial in establishing the net attraction within a given pair, and in this picture Friedel oscillations are considerably enhanced by quadratic response, subsequently playing a very important role in the overall pairing. Calculated vibron frequencies also show substantial agreement with experiment, reflecting at the same time significant changes in the physical character of the pairing itself.

Journal Article↗