STUDI STRUKTUR ION KADMIUM(II) TERSOLVASI DALAM AIR DAN AMONIAK CAIR MENGGUNAKAN SIMULASI DINAMIKA MOLEKULER

• Main Authors: , Wahyuni, , Dr.rer.nat. Ria Armunanto, M.Si.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2012
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/99074/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=54874
• Institution: Universitas Gadjah Mada

Study of structural properties of solvated Cd2+ ion in water and liquid ammonia has been carried out by means of the ab initio MD simulation approach. The most important region, the first solvation shell, was treated by quantum mechanics methods at HF as a comparison the validity results from the use of two-body potential without using three-body potential correction, by use of DZVP (DFT orbital) basis set for Cd2+, Def2-SV(P) basis set for H2O and NH3. The remaining region was treated by molecular mechanics method. Whereas for the transition region was used smoothing function. Fitting of energy to analytical functions using Lavenberg algorithm was done at Restricted Hartree-Fock (RHF) using basis set as mentioned above. Structural properties of solvated Cd2+ in water and ammonia liquid were characterized using RDF, CND, and ADF data obtained from the trajectory files. QM/MM DM simulation has characterized structural properties of solvated Cd2+ ion in water showing a flexible structure of the first solvation shell with various [Cd(H2O)n]2+ complex structures (n = 6,7 and 8). The solvation complexes with coordination numbers of 6.93 and 17.45 were observed for the first and second solvation shells, respectively. The highest occurrence of the [Cd(H2O)7]2+ spesies (65,91%) in the coordination number distribution indicates for the main solvates in the first salvation shell. Cd2+-O distances of 2.36 � and 3.58 � were observed for the first and second shells respectively, whereas Cd2+-H distance of 2.89 � and 4.64 �. The basis set Cd2+ ion has not been found yet that can describe the interaction between Cd2+ ion and liquid ammonia.