Harno Dwi Pranowo
Austrian-Indonesian Centre for Computational Chemistry Gadjah Mada University, Yogyakarta

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SOLVATION STRUCTURE DETERMINATION OF Ni2+ ION IN WATER BY MEANS OF MONTE CARLO METHOD Tutik Arindah; Bambang Setiaji; Harno Dwi Pranowo
Indonesian Journal of Chemistry Vol 2, No 3 (2002)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (225.912 KB) | DOI: 10.22146/ijc.21915

Abstract

Determination of solvation structure of Ni2+ ion in water has been achieved using Monte Carlo method using canonic assemble (NVT constant). Simulation of a Ni2+ ion in 215 H2O molecules has been done under NVT condition (298.15 K). The results showed that number of H2O molecules surround Ni2+ ion were 8 molecules in first shell and 17 molecules in second shell, interaction energy of Ni2+-H2O in first shell was -68.7 kcal/mol and in second shell was -9.8 kcal/mol, and there were two angles of O-Ni2+-O, i.e. 74o and 142o. According to those results, the solvation structure of Ni2+ ion in water was cubic antisymetric.
THE INTERACTION OF Co2+-AMMONIA MODELLING: THE COMPARATIVE STUDY BETWEEN AB INITIO AND ELECTRON CORRELATION METHODS Harno Dwi Pranowo; Foliatini Foliatini; Karna Wijaya
Indonesian Journal of Chemistry Vol 2, No 2 (2002)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (124.436 KB) | DOI: 10.22146/ijc.21916

Abstract

Research on comparison between Hartree-Fock method and electron correlation methods as well as the effect of size of basis sets on representing interaction of Co2+-NH3 observed from complex energy parameters and optimum geometric parameters have been carried out.The first step is screening basis sets based on charge transfer effect and BSSE value. The selected basis set does not yield charge transfer at 1,4 Å <  < 8 Å, and yield small BSSE value. Electron correlation methods used are Møller-Plesset order 2 (MP2), Møller-Plesset order 3 (MP3), Configuration Interaction, Doubles (CID), dan Configuration Interaction, Singles and Doubles (CISD) whereas the basis set used is the result of the screening. LANL2DZ ECP-6-31G* and LANL2DZ ECP-6-311++G(3df,3pd)  basis sets are used with Unrestricted Hartree-Fock (UHF) and Møller-Plesset order 2 (MP2) methods to study the effect of size of basis sets.The result of the research showed that the best basis set is LANL2DZ ECP for Co2+ and 6-31G* for NH3. The application of electron correlation method and large basis set can increase the quality of interaction representation of Co2+- NH3. Møller-Plesset (MP) perturbation method gives larger contribution to correlation energy than Configuration Interaction (CI) method.
DETERMINATION OF MANY-BODY EFFECT OF [Co(NH3)n]2+ (n=1-6) COMPLEXES BASE ON AB INITIO CALCULATIONS Harno Dwi Pranowo; Karna Wijaya; Bambang Setiaji; Rhano Setyan Janu
Indonesian Journal of Chemistry Vol 2, No 1 (2002)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (107.899 KB) | DOI: 10.22146/ijc.21926

Abstract

The computational chemistry calculation to determine the stabilization energy and ligand-ligand repulsion energies of [Co(NH3)n]2+ system was done by using LANL2DZ basis set for Co2+ and 6-31G* basis set for NH3 at the level theory of  unrestricted Hartree-Fock (UHF). Result from the calculation shows that the larger number of NH3 ligand present in the complex give the effect of the lower average binding energy per ligand molecule, i.e. -503,29 kJ/mol for [Co(NH3)]2+ and then decrease to -338,025 kJ/mol for octahedral [Co(NH3)6]2+ complex. A correlation between the number of ligand and the metal ion-ligand bond distance was studied. The result shows that the metal ion-ligand bond distance increases along with the larger number of the ligand. The calculation of average pair interaction energies between Co2+ and NH3 in [Co(NH3)n]2+ complexes were done in order to determine the error possibility caused by the neglect of non-additivity contribution. The results indicate that the maximum relative error with respect to the pair potential, %ΔEavpi, is 17,64 % [Co(NH3)6]2+ complex.