Abstract
Abstract We developed the energy and its analytic gradient for the self-consistent-charge density-functional tight-binding method with the third-order expansion (DFTB3) combined with the fragment molecular orbital (FMO) method, FMO-DFTB3. FMO-DFTB3 reproduced full DFTB3 relative stabilities and the optimized structures of three polyalanine isomers. FMO-DFTB3 was applied to optimize a nano flake of cellulose Iβ, consisting of 10 944 atoms, and a good agreement with the experimental structure was obtained. For a cellulose sheet containing 1368 atoms, FMO-DFTB3 was 43.5 times faster than full DFTB3. The binding between sheets and chains in cellulose was elucidated, and two dispersion models were compared.
Original language | English |
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Article number | 33152 |
Pages (from-to) | 90-96 |
Number of pages | 7 |
Journal | Chemical Physics Letters |
Volume | 636 |
DOIs | |
State | Published - Aug 5 2015 |
Externally published | Yes |
Funding
The authors thank the Research Center for Computational Science, Okazaki, Japan for providing computational resources. Y.N. is supported by a Research Fellowships of the Japan Society for Promotion of Science for Young Scientists (DC1), and the L-Daigakuin program. D.G.F. acknowledges support of the Next Generation Super Computing Project, Nanoscience Program (MEXT, Japan) and D.G.F. and S.I. are grateful for support from the Computational Materials Science Initiative (CMSI, Japan).