Research papers
2001 · Journal of Computational Chemistry · 10,114 citations
Abstract We present the theoretical and technical foundations of the Amsterdam Density Functional (ADF) program with a survey of the characteristics of the code (numerical integration, density fitting for the Coulomb potential, and STO basis functions). Recent developments enhance the efficiency of ADF (e.g., parallelization, near order‐N scaling, QM/MM) and its functionality (e.g., NMR chemical shifts, COSMO solvent effects, ZORA relativistic method, excitation energies, frequency‐dependent (hyper)polarizabilities, atomic VDD charges). In the Applications section we discuss the physical model of the electronic structure and the chemical bond, i.e., the Kohn–Sham molecular orbital (MO) theory, and illustrate the power of the Kohn–Sham MO model in conjunction with the ADF‐typical fragment approach to quantitatively understand and predict chemical phenomena. We review the “Activation‐strain TS interaction” (ATS) model of chemical reactivity as a conceptual framework for understanding how activation barriers of various types of (competing) reaction mechanisms arise and how they may be controlled, for example, in organic chemistry or homogeneous catalysis. Finally, we include a brief discussion of exemplary applications in the field of biochemistry (structure and bonding of DNA) and of time‐dependent density functional theory (TDDFT) to indicate how this development further reinforces the ADF tools for the analysis of chemical phenomena. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 931–967, 2001
2017 · Journal of Physics Condensed Matter · 7,665 citations
Quantum EXPRESSO is an integrated suite of open-source computer codes for quantum simulations of materials using state-of-the-art electronic-structure techniques, based on density-functional theory, density-functional perturbation theory, and many-body perturbation theory, within the plane-wave pseudopotential and projector-augmented-wave approaches. Quantum EXPRESSO owes its popularity to the wide variety of properties and processes it allows to simulate, to its performance on an increasingly broad array of hardware architectures, and to a community of researchers that rely on its capabilities as a core open-source development platform to implement their ideas. In this paper we describe recent extensions and improvements, covering new methodologies and property calculators, improved parallelization, code modularization, and extended interoperability both within the distribution and with external software.
1982 · The Journal of Chemical Physics · 6,501 citations
The coupled-cluster singles and doubles model (CCSD) is derived algebraically, presenting the full set of equations for a general reference function explicitly in spin–orbital form. The computational implementation of the CCSD model, which involves cubic and quartic terms, is discussed and results are reported and compared with full CI calculations for H2O and BeH2. We demonstrate that the CCSD exponential ansatz sums higher-order correlation effects efficiently even for BeH2, near its transition state geometry where quasidegeneracy efforts are quite large, recovering 98% of the full CI correlation energy. For H2O, CCSD plus the fourth-order triple excitation correction agrees with the full CI energy to 0.5 kcal/mol. Comparisons with low-order models provide estimates of the effect of the higher-order terms T1T2, T21T2, T31, and T41 on the correlation energy.
1982 · Physical Review Letters · 5,683 citations
A simple way has been discovered to put model pseudopotentials, $V(\stackrel{\ensuremath{\rightarrow}}{\mathrm{r}})={\ensuremath{\Sigma}}_{\mathrm{lm}}|{Y}_{\mathrm{lm}}〉{V}_{l}(r)\ifmmode\times\else\texttimes\fi{}〈{Y}_{\mathrm{lm}}|$, into a form which reduces the number of integrals of $V(\stackrel{\ensuremath{\rightarrow}}{\mathrm{r}})$ required for an energyband calculation from $\frac{\mathrm{mn}(n+1)}{2}$ to $\mathrm{mn}$ for each $l$ in the sum (where $n$ is the number of plane waves used in the expansion and $m$ the number of points in the Brillouin zone at which the calculation is performed). The new form may be chosen to improve the accuracy of the pseudopotential when used in other chemical environments.
1970 · Progress of Theoretical Physics · 21 citations
Journal of the Physical Society of Japan 69 (2000) pp. 1449-1456 Kondo Resonance in a Quantum Dot: Finite-U Anderson Model out of Equilibrium Daichi Matsumoto Progress of Theoretical Physics Vol. 43 No. 6 (1970) pp. 1458-1479 Self-Consistent Treatment of Anderson Model and Magnetic Susceptibility Hiroshi Mamada and Fumihiko Takano Progress of Theoretical Physics Vol. 44 No. 1 (1970) pp. 59-76 Self-Consistent Treatment of the Wolff-Moriya Model Fumiaki Shibata and Hiroshi Mamada Progress of Theoretical Physics Vol. 45 No. 4 (1971) pp. 1028-1049 On the Singularity in Anderson Model. I Hiroshi Mamada and Fumiaki Shibata
1962 · Progress of Theoretical Physics · 3 citations
Progress of Theoretical Physics Vol. 29 No. 2 (1963) pp. 235-254 Coupled Partial-Wave-Dispersion-Relation for Nucleon-Nucleon Scattering and ρ- and ω-meson Contributions Susumu Furuichi Progress of Theoretical Physics Vol. 30 No. 3 (1963) pp. 327-342 Contributions of KK Intermediate State to Nucleon Form Factors Ghanshyam Prasad Singh
1992 · AIP conference proceedings
The objective of this paper is to provide a short introduction of some of the theoretical issues in out‐of‐plane (e,e’X) reactions. To this end, a general form of the cross section for such reactions is presented and discussed within the context of three examples of such processes.