Molecular simulations and quantum chemical calculations have been employed to study solubility, adsorption, membrane permeation and reaction processes; the first goal is to deeply understand the phenomena at the molecular level and the second is to develop computing tools for molecular design useful for advanced separation technologies and reaction controls. A non-equilibrium molecular dynamics (NEMD) method has been developed and used for studying permeation of gases through inorganic membranes. Recently, computer programs for an ab initio MD method and a hybrid QM/MM method have been developed for studying dynamical behavior of solvated molecules and reaction paths in supercritical fluids.
Shin-ichi Furukawa, Satoshi Kato and Tomoshige Nitta: Molecular Dynamics Studies on Clustering Process of Solute Molecules through Rapid Expansion of Supercritical Fluids, Fluid Phase Equil., in press
Takumi Hori, Hideaki Takahashi, and Tomoshige Nitta: Hybrid quantum chemical studies for the methanol formation reaction assisted by the proton transfer mechanism in supercritical water; CH3Cl + nH2O -> CH3OH + HCl + (n-1) H2O, Journal of Chemical Physics, 119(16), 8492-8499 (2003)
Hideaki Takahashi, Hideaki Hashimoto, and Tomoshige Nitta: Quantum mechanical/molecular mechanical studies of a novel reaction catalyzed by proton transfers in ambient and supercritical states of water, Journal Chemical Physics, 119(15), 7964-7971 (2003)
Yi Zhang, Shin-ichi Furukawa and Tomoshige Nitta: Molecular Simulation Studies on Adsorption of Propane/Propylene in NaA zeolite by Using a Monte Carlo Technique, J. Chem. Eng. Japan, 36(9), 1085-1094 (2003)
Hideaki Takahashi, Shigeki Takei, Takumi Hori, and Tomoshige Nitta: A real-space-grid QM/MM study on the ionic/radical association reaction in aqueous phase: HCHO + OH -> HCHO-OH, Journal of Molecular Structure (Theochem), 632, 185-195 (2003)
Yi Zhang, Shin-ichi Furukawa and Tomoshige Nitta: Computer Simulation Studies on Gas Permeation of Propane and Propylene across ZSM-5 Membranes by a Non-Equilibrium Molecular Dynamics Technique, Separation and Purification Technology, 32(1-3), 215-221 (2003)
Shin-ichi Furukawa and Tomoshige Nitta: A Study of Permeation of n-Butane in ZSM-5 by using Monte Carlo and Equilibrium/Non-Equilibrium Molecular Dynamics Simulations, J. Chem. Eng. Japan, 36(3), 313-321 (2003)
Hori T., H. Takahashi, and T. Nitta: Hybrid QM/MM Molecular Dynamics Simulations for an Ionic SN2 Reaction in the Supercritical Water: OH- + CH3Cl CH3OH + Cl-, J. Computational Chem. 24(12), 209-221 (2003)
Hideaki Takahashi, Shumpei Hisaoka, Tomoshige Nitta: Ethanol Oxidation Reactions Catalyzed by Water Molecules: CH3CH2OH + nH2O CH3CHO + H2 + H2O (n=0,1,2), Chem. Phys. Lett., 363(12), 80-86 (2002)
Chong Gu, Guang-Hua Gao, Yang-Xin Yu and Tomoshige Nitta: Simulation for Separation of Hydrogen and Carbon Monoxide by Adsorption on Single-Walled Carbon Nanotubes, Fluid Phase Equil., 194-197, 297-307 (2002)
Furukawa, S., C. McCabe, P.T. Cummings, and T. Nitta: Non-equilibrium Molecular Dynamics Simulation Studies on Behavior of Hydrocarbon-isomers in Silicalite, Fluid Phase Equil., 194-197, 309-317 (2002)
Takahashi, H., K. Yuki, and T. Nitta: Chemical modification of rutile TiO2 (110) surface by ab initio calculations for the purpose of CO2 adsorption, Fluid Phase Equil., 194-197, 153-160 (2002)
Takahashi H., T. Hori, T. Wakabayashi and T. Nitta: Ab initio Molecular Dynamics Simulations of an OH Radical / OH Anion with a Solvated Formaldehyde Molecule, Foundations of Molecular Modeling and Simulation, AIChE Symp. Ser. No. 325, vol. 97, 280-282 (2001)
Takahashi, H., T. Hori, H. Hashimoto and T. Nitta: A Hybrid QM/MM Method Employing Real Space Grids for QM Water in the TIP4P Water Solvents, J. Computational Chem., 22(12), 1252-1261 (2001)
Takahashi, H., T. Hori, T. Wakabayashi, and T. Nitta: Real Space Ab Initio Molecular Dynamics Simulations for the Reactions of OH Radical/OH Anion with Formaldehyde, J. Phys. Chem. A, 105(17), 4351-4358 (2001)
Nitta, T. and S. Furukawa: Simulation Performance of a Non-Equilibrium Molecular Dynamics Method using Density Difference as Driving Force, Molecular Simulation, 25, 197-208 (2000)
Furukawa, S. and T. Nitta: Non-equilibrium molecular dynamics simulation studies on gas permeation through carbon membranes with different pore shape composed of micro-graphite crystallites, J. Membrane Sci., 178, 107-119 (2000)
Takahashi, H., T. Hori, T. Wakabayashi and T. Nitta; A Density Functional Study for Hydrogen Bond Energy by Employing Real Space Grids, Chemistry Letters, No.3, 222-223 (2000)
Takahashi, T., K. Okuda and T. Nitta; Chemical Modification of MgO (001) Surface by Utilizing Energy Decomposition Analyses for the Purpose of CO2 Adsorption, Bull. Chem. Soc. Jpn., 73, 315-319 (2000)
Furukawa, S., T. Sugahara and T. Nitta; Non-equilibrium MD Studies on Gas Permeation through Carbon Membranes with Belt-like Heterogeneous Surfaces, J. Chem. Eng. Japan, 32(2), 223-228 (1999)
Shigeta, T. and T. Nitta; Monte Carlo Simulation Study of Entrainer Effect on Distribution Equilibrium between Supercritical Fluids and Slitpores, J. Chem. Eng. Japan, 32(1),150-152 (1999)
Takahashi, H., T. Wakabayashi and T. Nitta; A wavepacket analysis of the statistical behaviour of molecules that penetrate a slit-shaped micropore, Chem. Phys. Letters, 294, 95-102 (1998)
Nitta, T. and T. Shigeta; Computer Simulation Studies of Adsorption Characteristics in Supercritical Fluids, Fluid Phase Equilibria, 144(1-2), 245-256 (1998)
Takahashi, H., Nakamura, and T. Nitta; Effect of the Shape of Simulation Box on the van der Waals loop of Lennard-Jones Fluid, Chem. Phys. Letters, 282, 128-132 (1998)
Furukawa, S., K. Hayashi and T. Nitta; Effects of Surface Heterogeneity on Gas Permeation through Slitlike Carbon Membranes by Non-Equilibrium Molecular Dynamics Simulations, J. Chem. Eng. Japan, 30(6), 1107-1112 (1997)
Furukawa, S. and T. Nitta: Computer Simulation Studies on Gas Permeation through Nanoporous Carbon Membranes by Non-Equilibrium Molecular Dynamics, J. Chem. Eng. Japan, 30(1), 116-122 (1997)
Nitta, T., H. Kiriyama and T. Shigeta; Monte Carlo Simulation Study for Adsorption of Dimers on Random Heterogeneous Surface, Langmuir, 13(5), 903-908 (1997)
Furukawa, S., T. Shigeta and T. Nitta: Non-Equilibrium Molecular Dynamics for Simulating Permeation of Gas Mixtures through Nanoporous Carbon Membranes, J. Chem. Eng. Japan, 29(4), 725-728 (1996)