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Internet Electronic Journal of Molecular Design - IEJMD, ISSN 1538-6414, CODEN IEJMAT
| ABSTRACT - Internet Electron. J. Mol. Des. September 2002, Volume 1, Number 9, 450-461 |
Calculation of the Tunneling Splittings in Water Trimer with a
Genetic Algorithm
Michihiko Sugawara, Hiromi Nakanishi, and Satoshi Yabushita
Internet Electron. J. Mol. Des. 2002, 1, 450-461
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Abstract:
Although inter-molecular interaction in water cluster has been a
subject of significant interest for many years, there have been very
few of fully quantum mechanical studies because of the numerical
difficulties associated with the multi-dimensional Schrödinger
equation. In this study, vibrational eigenstates/eigenenergies with
respect to three-dimensional hydrogen flipping motion in the water
trimer (WT) are solved by utilizing a hybrid micro genetic
algorithm (μ-GA). Hybrid μ-GA is employed to solve the
Schrödinger equation, in which the conventional variational
calculation is combined at the final stage to overcome the μ-GA's
disadvantage, namely the slow convergence to the exact solution.
Eigenstates and eigenvalues calculated by hybrid μ-GA are found
to be in good agreement with the ones obtained by the discrete
variable method. From the eigenvalue differences, tunneling time
associated with the flipping motion of WT is evaluated to be 1.2 ns.
Hybrid μ-GA together with the stochastically defined fitness score
makes it possible to calculate efficiently the three-dimensional
vibrational eigenenergies/eigenstates of the hydrogen flipping
motion in WT.
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