@article{5382702c3c2f410e83c28e381a234aee,
title = "Density-functional tight-binding combined with the fragment molecular orbital method",
abstract = "We developed the energy and its gradient for the self-consistent-charge density-functional tight-binding (DFTB) method, combined with the fragment molecular orbital (FMO) approach, FMO-DFTB, including an optional a posteriori treatment for dispersion interaction, and evaluated its accuracy as well as computational efficiency for a set of representative systems: polypeptides, a DNA segment, and a small protein. The error in the total energy of FMO-DFTB versus full SCC-DFTB was below 1 kcal/mol for the polyalanine system consisting of about 2000 atoms partitioned into fragments containing 2 residues, and the optimized structures had root-mean-square deviations below 0.1 {\AA}. The scaling of FMO-DFTB with the system size N is only marginally larger than linear [O(N1.2) in the worst case]. A parallelization efficiency of 94% was achieved using 128 CPU cores, and we demonstrate the applicability of FMO-DFTB for systems containing more than one million atoms by performing a geometry optimization of a fullerite cluster.",
author = "Yoshio Nishimoto and Fedorov, {Dmitri G.} and Stephan Irle",
note = "Publisher Copyright: {\textcopyright} 2014 American Chemical Society.",
year = "2014",
month = nov,
day = "11",
doi = "10.1021/ct500489d",
language = "English",
volume = "10",
pages = "4801--4812",
journal = "Journal of Chemical Theory and Computation",
issn = "1549-9618",
publisher = "American Chemical Society",
number = "11",
}