Molecular dynamics study of an aqueous potassium nitrate solution

✍ Scribed by Christoph Ebner; Roland Sansone; Sunantha Hengrasmee; Michael Probst

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 554 KB
• Volume: 75
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1999)75:4/5<805::aid-qua45>3.0.co;2-y

✦ Synopsis

We report the results of a molecular dynamics simulation on the system KNO rH O. For the interaction between nitrate anion, water molecule, and potassium 3 2 cation, newly developed analytical potentials were employed whereas the water᎐water interactions were described with the MCYL potential. Water and nitrate anion were treated as flexible molecules. The periodic box contained 341 water molecules, 1 nitrate anion, and 1 potassium cation. The structure of the hydration shell is investigated in terms of radial and angular distribution functions. The vibrational density of states is calculated to derive information about the frequency shifts of the anion upon hydration and of the surrounding water molecules. We compare the findings of our simulations with other molecular dynamics simulations involving nitrate anion and with quantum chemical reaction field calculations. Our simulations show a well-defined but orientationally very flexible hydration shell and small gas-to-liquid frequency shifts for both nitrate anion and hydration shell water molecules.