<i>Ab Initio</i> Fragment Molecular Orbital-Based Molecular Dynamics (FMO-MD) Simulations of (NH3)32 Cluster: Effects of Electron Correlation

• Moeko Ninomiya

  Department of Chemistry and Research Center for Smart Molecules, Faculty of Science, Rikkyo University, 3-34-1 Nishi-ikebukuro, Toshima-ku, Tokyo 171-8501 , Japan

• Hideo Doi

  Department of Chemistry and Research Center for Smart Molecules, Faculty of Science, Rikkyo University, 3-34-1 Nishi-ikebukuro, Toshima-ku, Tokyo 171-8501 , Japan

• Yoshiteru Matsumoto

  Department of Chemistry, Faculty of Science, Shizuoka University, 836 Ohya, Suruga, Shizuoka 422-8529 , Japan

• Yuji Mochizuki

  Department of Chemistry and Research Center for Smart Molecules, Faculty of Science, Rikkyo University, 3-34-1 Nishi-ikebukuro, Toshima-ku, Tokyo 171-8501 , Japan

• Yuto Komeiji

  Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, AIST, Tsukuba Central 6, Tsukuba, Ibaraki 305-8566 , Japan

Abstract

An isolated cluster of 32 ammonia (NH3) molecules was simulated at 50 and 100 K by the ab initio fragment molecular orbital based molecular dynamics (FMO-MD) method to analyze the effect of electron correlation via second-order Møller–Plesset perturbation (MP2). Both the energy and force of the system were calculated at the MP2 and Hartree-Fock (HF) levels with the 6-31G** basis set. The radial distribution and angular distribution functions were obtained from the trajectories. A comparison of MP2 and HF suggested that the electron-correlation effect via MP2 leads to relative condensation through electron delocalization, similar to the case of water. Vibrational spectra were also calculated at both the MP2 and HF levels, and the former gave a more minute split of the higher modes. This again suggested that MP2 better describes the electron delocalization.

Journal

• Bulletin of the Chemical Society of Japan

  Bulletin of the Chemical Society of Japan 93 (4), 553-560, 2020-02-06

  Oxford University Press (OUP)

Keywords

• General Chemistry

Details

• CRID: 1360567007945455104
• NII Article ID: 130007831644
• DOI: 10.1246/bcsj.20190320
• ISSN: 13480634
• ISSN: 00092673
• Web Site: https://academic.oup.com/bcsj/article-pdf/93/4/553/56303744/bcsj.20190320.pdf
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