作者：
Guo, WenpingWu, AnanZhang, Igor YingXu, XinXiamen Univ
Coll Chem & Chem Engn State Key Lab Phys Chem Solid Surface Xiamen 361005 Peoples R China Xiamen Univ
Coll Chem & Chem Engn Fujian Prov Key Lab Theoret & Computat Chem Xiamen 361005 Peoples R China Fudan Univ
Dept Chem MOE Lab Computat Phys Sci Shanghai Key Lab Mol Catalysis & Innovat Mat Shanghai 200433 Peoples R China
Calculation of large complex systems remains to be a great challenge, where there is always a trade-off between accuracy and efficiency. Recently, we proposed the extended our own n-layered integrated molecular orbita...
详细信息
Calculation of large complex systems remains to be a great challenge, where there is always a trade-off between accuracy and efficiency. Recently, we proposed the extended our own n-layered integrated molecular orbital (ONIOM) method (XO) (Guo, Wu, Xu, Chem. Phys. Lett. 2010, 498, 203) which surmounts some inherited limitations of the popular ONIOM method by introducing the inclusion-exclusion principle used in the fragmentation methods. The present work sets up general guidelines for the construction of a good XO scheme. In particular, force-error test is proposed to quantitatively validate the usefulness of an XO scheme, taking accuracy, efficiency and scalability all into account. Representative studies on zeolites, polypeptides and cyclodextrins have been carried out to demonstrate how to strive for high accuracy without sacrificing efficiency. As a natural extension, XO is applied to calculate the total energy, fully optimized geometry and vibrational spectra of the whole system, where ONIOM becomes inapplicable. (c) 2012 Wiley Periodicals, Inc.
The past years since the publication of our review on subsystem density-functional theory (sDFT) (WIREs Comput Mol Sci. 2014, 4:325-362) have witnessed a rapid development and diversification of quantum mechanical fra...
详细信息
The past years since the publication of our review on subsystem density-functional theory (sDFT) (WIREs Comput Mol Sci. 2014, 4:325-362) have witnessed a rapid development and diversification of quantum mechanical fragmentation and embedding approaches related to sDFT and frozen-density embedding (FDE). In this follow-up article, we provide an update addressing formal and algorithmic work on sDFT/FDE, novel approximations developed for treating the non-additive kinetic energy in these DFT/DFT hybrid methods, new areas of application and extensions to properties previously not accessible, projection-based techniques as an alternative to solely density-based embedding, progress in wavefunction-in-DFT embedding, new fragmentation strategies in the context of DFT which are technically or conceptually similar to sDFT, and the blurring boundary between advanced DFT/MM and approximate DFT/DFT embedding methods. This article is categorized under: Electronic Structure Theory > Density Functional Theory
The elongation cutoff technique ELG/C belongs to fragmentation methods. It uses the concept of locality and takes into account the sparsity of Kohn-Sham (KS) matrix in regionally localized molecular orbital basis set....
详细信息
The elongation cutoff technique ELG/C belongs to fragmentation methods. It uses the concept of locality and takes into account the sparsity of Kohn-Sham (KS) matrix in regionally localized molecular orbital basis set. In this article, a linear-scaling implementation of ELG/C method at Kohn-Sham (KS) level of theory is presented. Its efficiency and accuracy is discussed for model system. The ELG/C KS scheme is based on local exchange-correlation space approximation. Such approximation improves efficiency of the method and does not introduce a significant error. The current analysis includes the overall CPU (central processing unit) time and its most time consuming steps. The obtained results indicate that the ELG/C is a very efficient and accurate computational scheme. (C) 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110:2130-2139, 2010
We review the role of self-consistency in density functional theory (DFT). Weapply a recent analysis to both Kohn-Sham and orbital-free DFT, as well as to partition DFT, which generalizes all aspects of standard DFT. ...
详细信息
We review the role of self-consistency in density functional theory (DFT). Weapply a recent analysis to both Kohn-Sham and orbital-free DFT, as well as to partition DFT, which generalizes all aspects of standard DFT. In each case, the analysis distinguishes between errors in approximate functionals versus errors in the self-consistent density. This yields insights into the origins of many errors in DFT calculations, especially those often attributed to self-interaction or delocalization error. In many classes of problems, errors can be substantially reduced by using better densities. We review the history of these approaches, discuss many of their applications, and give simple pedagogical examples.
Electronic couplings are crucial for understanding exciton dynamics and associated energy transfer in artificial and natural chromophores. The proposed PyFREC (Python FRagment Electronic Coupling) software enables eva...
详细信息
Electronic couplings are crucial for understanding exciton dynamics and associated energy transfer in artificial and natural chromophores. The proposed PyFREC (Python FRagment Electronic Coupling) software enables evaluation of electronic couplings based on the Forster model. PyFREC features the decomposition of electronic couplings, obtained through quantum chemical calculations, into the orientation and dipole strength components. Furthermore, the variation method to evaluate energies of coupled electronic excited states and delocalization of electronic excitations is implemented in the software. PyFREC has been tested on the S22 benchmark dataset of non-covalent complexes and water clusters. (c) 2016 Wiley Periodicals, Inc.
A molecular fragmentation method is used to study the stability of cyclophane derivates by decomposing the molecular energy into the molecular strain and intramolecular interaction energies. The molecular strain energ...
详细信息
A molecular fragmentation method is used to study the stability of cyclophane derivates by decomposing the molecular energy into the molecular strain and intramolecular interaction energies. The molecular strain energies obtained by utilising the fragmentation method are in good agreement with existing experimental data. The intramolecular interaction energies calculated as the difference between the supermolecular energy and the bonded fragment energies are repulsive in the cyclophanes studied. The nature of this interaction is studied for groups of systematically extended doubled layered paracyclophane systems using the random-phase approximation (RPA), two recently developed extensions to the RPA and standard density functional theory (DFT) methods including dispersion corrections. Upon a systematic increase in conjugation the strongly repulsive intramolecular interaction energy reduces and thus leads to an increase in the stability. Finally, existing experimental and theoretical estimates of the molecular strain are compared with the results of this work.
暂无评论