SIMULASI DINAMIKA MOLEKULER HIBRIDA MEKANIKA KUANTUM /MEKANIKA MOLEKULER ION Y2+ DALAM AMONIAK CAIR DAN AIR; A HYBRID QM/MM MD SIMULATION FOR Y2+ ION IN LIQUID AMMONIA AND WATER

Sukir, Ria Armunanto

2011 | Disertasi | PROGRAM STUDI S2 KIMIA

Structural study on solvation of Y2+ ion in liquid ammonia and water has been done by using a hybrid QM/MM MD simulation. Fitting of energy to analytical functions using Lavenberg algorithm was done at level of UHF (Unrestricted Hartree-Fock) using DZVP (DFT Orbital) basis sets for Y and SV(P) for O, N and H (water and ammonia), respectively. Simulation box was divided into two part (the QM and MM regions, whereas for the transition region was used Smoothing function). Solvation structure properties of Y2+ ion in liquid ammonia and water were characterized using RDF, CND, and ADF data obtained from trajectory files (configuration coordinate every simulation step). Y2+ ion in liquid ammonia was solvated to give a flexible complex structure with 4.8 and 12.9 coordination numbers at first and second shell respectively, Y2+-N distances of 2.55 Å and 4.80 Å at first and second shell respectively, Y2+-H distances of 3.09 Å and 5.80 Å at first and second shell respectively and N-Y2+-N angles dominant at first shell were 84°, 110°, 120° and 160°. Y2+ ion in water was solvated to give a flexible complex structure with 7.3 and 15.9 coordination numbers at first and second shell respectively, Y2+-O distances of 2.45 Å and 4.33 Å at first and second shell respectively and Y2+-H distances of 3.13 Å and 5.50 Å at first and second shell respectively.

Kata Kunci : DM MK/MM, solvasi, Y2+