The K+ hydration shell structure in non-polar and low-polar environments

► Calculations on K+(H2O)n hydrates in non-polar and low-polar media. ► Hydration number drops with increasing dielectric constant. ► Non-polar media: mono and dihydrates are the major species. ► Low-polar media: cation hydrate formation is an endergonic process. ► Most-stable hexahydrates has four water molecules in the first shell.