We present an efficient analytical approach using analytical eigensolution of symmetric tridiagonal two-Toeplitz matrix and second perturbation technique for predicting the magnitude of structural distortion due to Peierls instability in organic molecular crystals. The accuracy of this method was verified for several model molecular systems, such as two-dimensional ethylene, benzene, and tetrathiafulvalene cation monolayers at the extended-Hückel molecular orbital level of theory. In all of these calculations, our analytical approach provides the accurate magnitude of Peierls distortion within an error of 0.04 Å. Additionally, the computational time required for obtaining the total energy is drastically saved in our method. For a large system, such as a 34×4 benzene cation monolayer, the CPU time for computing the total energies is as small as 1 200 of that by calculations using direct diagonalization. As an application for real system, a comparison of experimental and theoretical crystal structure of 1,3,5-trithia-2,4,6-triazapentalenyl crystal was performed. When using our analytical method, the deviation of some geometrical parameters from experimental data is extensively small and 99% of required CPU time is saved compared to the direct calculation.
|ジャーナル||Physical Review B - Condensed Matter and Materials Physics|
|出版ステータス||出版済み - 4 2 2008|
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