Browsing Duke Faculty Scholarship by Author "0110948"

Now showing items 1-10 of 10

Accelerating self-consistent field convergence with the augmented Roothaan-Hall energy function

Hu, Xiangqian; Yang, Weitao (AMER INST PHYSICS, 2010)

Based on Pulay's direct inversion iterative subspace (DIIS) approach, we present a method to accelerate self-consistent field (SCF) convergence. In this method, the quadratic augmented Roothaan-Hall (ARH) energy function, ...
Conductive junctions with parallel graphene sheets

Zheng, Xiao; Ke, San-Huang; Yang, Weitao (AMER INST PHYSICS, 2010)

The establishment of conductive graphene-molecule-graphene junction is investigated through first-principles electronic structure calculations and quantum transport calculations. The junction consists of a conjugated ...
Efficient Construction of Nonorthogonal Localized Molecular Orbitals in Large Systems

Cui, Ganglong; Yang, Weitao (AMER CHEMICAL SOC, 2010)

Localized molecular orbitals (LMOs) are much more compact representations of electronic degrees of freedom than canonical molecular orbitals (CMOs) The most compact representation is provided by nonorthogonal localized ...
Elucidating Solvent Contributions to Solution Reactions with Ab Initio QM/MM Methods

Hu, Hao; Yang, Weitao (AMER CHEMICAL SOC, 2010)

Computer simulations of reaction processes in solution in general rely on the definition of a reaction coordinate and the determination of the thermodynamic changes of the system along the reaction coordinate. The reaction ...
Predicting the Frequency Dispersion of Electronic Hyperpolarizabilities on the Basis of Absorption Data and Thomas-Kuhn Sum Rules

Hu, Xiangqian; Xiao, Dequan; Keinan, Shahar; Therien, Michael; Yang, Weitao; Beratan, David (AMER CHEMICAL SOC, 2010)

Successfully predicting the frequency dispersion of electronic hyperpolarizabilities is an unresolved challenge in materials science and electronic structure theory. We show that the generalized Thomas-Kuhn sum rules, ...
Reformulating time-dependent density functional theory with non-orthogonal localized molecular orbitals

Cui, Ganglong; Yang, Weitao (ROYAL SOC CHEMISTRY, 2010)

Time-dependent density functional theory (TDDFT) has broad application in the study of electronic response, excitation and transport. To extend such application to large and complex systems, we develop a reformulation of ...
Revealing Noncovalent Interactions

Johnson, Erin; Keinan, Shahar; Mori-Sanchez, Paula; Contreras-Garcia, Julia; Yang, Weitao (AMER CHEMICAL SOC, 2010)

Molecular structure does not easily identify the intricate noncovalent interactions that govern many areas of biology and chemistry, including design of new materials and drugs. We develop an approach to detect noncovalent ...
Spin-state splittings, highest-occupied-molecular-orbital and lowest-unoccupied-molecular-orbital energies, and chemical hardness

Johnson, Erin; Yang, Weitao (AMER INST PHYSICS, 2010)

It is known that the exact density functional must give ground-state energies that are piecewise linear as a function of electron number. In this work we prove that this is also true for the lowest-energy excited states ...
Structural manifestation of the delocalization error of density functional approximations: C4N+2 rings and C-20 bowl, cage, and ring isomers

Heaton-Burgess, Tim; Yang, Weitao (AMER INST PHYSICS, 2010)

The ground state structure of C4N+2 rings is believed to exhibit a geometric transition from angle alternation (N 2). All previous density functional theory (DFT) studies on these molecules have failed to reproduce this ...
Time-dependent transport through molecular junctions

Liu, Rui; Yang, Weitao (AMER INST PHYSICS, 2010)

We investigate transport properties of molecular junctions under two types of bias-a short time pulse or an ac bias-by combining a solution for Green's functions in the time domain with electronic structure information ...