A new 3D grid method for accurate electronic structure calculation of polyatomic molecules: The Voronoicell finite difference method
SangKil Son and ShihI Chu
The 39th Meeting of the Division of Atomic, Molecular and Optical Physics (American Physics Society, State College, Pennsylvania, May 2731, 2008) [poster] [BibTeX][slide: 607kb]http://meetings.aps.org/link/BAPS.2008.DAMOP.L2.14
We introduce a new computational method on unstructured grids in the threedimensional (3D) spaces to investigate the electronic structure of polyatomic molecules.
The Voronoicell finite difference (VFD) method realizes a simple discrete Laplacian operator on unstructured grids based on Voronoi cells and their natural neighbors.
The feature of unstructured grids enables us to choose intuitive pictures for an optimal molecular grid system.
The new VFD method achieves highly adaptability by the Voronoicell diagram and yet simplicity by the finite difference scheme. It has no limitation in local refinement of grids in the vicinity of nuclear positions and provides an explicit expression at each grid without any integration.
This method augmented by unstructured molecular grids is suitable for solving the Schrödinger equation with the realistic 3D Coulomb potentials regardless of symmetry of molecules.
For numerical examples, we test accuracies for electronic structures of oneelectron polyatomic systems: linear H_{2}^{+} and triangular H_{3}^{++}.
We also extend VFD to the density functional theory (DFT) for manyelectron polyatomic molecules.
[ Bulletin of the American Physical Society, Vol. 53, No. 7, p. 88 ] Tags: VFD,
Voronoi,
molecule,
H2+,
H3++,
H2O,
N2,
benzene,
KU
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