C. Froese Fischer and D. Ellis

... The programs that generate expansions deal in terms of subshells of configurations, without regard to coupling [13, 14]. For a given case, electrons are assigned to subshells. Electrons are then replaced by electrons from a list of allowed subshells according to some rule, and then all possible conf ...

... The programs that generate expansions deal in terms of subshells of configurations, without regard to coupling [13, 14]. For a given case, electrons are assigned to subshells. Electrons are then replaced by electrons from a list of allowed subshells according to some rule, and then all possible conf ...

Perspective: Fifty years of density-functional theory in chemical physics

... densities from other sources, TFD energies have errors of around 10%, too large for computational purposes. Furthermore, Teller deduced13 that Thomas-Fermi theory cannot bind molecules. TFD is useful for rough estimates of atomic properties only. Shell structure is a consequence of the Pauli exclusi ...

... densities from other sources, TFD energies have errors of around 10%, too large for computational purposes. Furthermore, Teller deduced13 that Thomas-Fermi theory cannot bind molecules. TFD is useful for rough estimates of atomic properties only. Shell structure is a consequence of the Pauli exclusi ...

Establishing Quantum Monte Carlo and Hybrid Density Functional

... require a solution of the fundamental many-electron Schrödinger equation. Since an exact solution of Schrödinger’s equation is intractable, several numerical methods have been developed to obtain approximate solutions. Currently, the two most successful methods are density functional theory (DFT) ...

... require a solution of the fundamental many-electron Schrödinger equation. Since an exact solution of Schrödinger’s equation is intractable, several numerical methods have been developed to obtain approximate solutions. Currently, the two most successful methods are density functional theory (DFT) ...

Ultracold Fermions in Two-Dimensional Planes with Dipolar

... in the rovibrational ground state. The strategy which lead to success was to first cool down atoms and then coherently convert them to ground state molecules at low temperatures without heating the sample. Mainly this is done by the use of Feshbach resonance to switch the interaction after the cooli ...

... in the rovibrational ground state. The strategy which lead to success was to first cool down atoms and then coherently convert them to ground state molecules at low temperatures without heating the sample. Mainly this is done by the use of Feshbach resonance to switch the interaction after the cooli ...

Chem Soc Rev - [ RSC ] Publishing

... a detailed study on the equilibrium between the peroxo and bis(m-oxo) isomers of [Cu2(en)2(O)2]2+. In this case, the scan of the potential energy surface (PES) connecting the two structures was conducted using LPNO-CCSD energies in the complete basis set limit complemented with canonical perturbativ ...

... a detailed study on the equilibrium between the peroxo and bis(m-oxo) isomers of [Cu2(en)2(O)2]2+. In this case, the scan of the potential energy surface (PES) connecting the two structures was conducted using LPNO-CCSD energies in the complete basis set limit complemented with canonical perturbativ ...

Ab initio Calculations of Optical Rotation

... smells like speariment, while its right-handed counterpart smells like caraway. 1 (R)-limonene is found in orange peels, while the (S ) enantiomer is present in lemons.2 Often, one enantiomer produces a characteristic effect, while the other either produces no effect at all, or has a totally differe ...

... smells like speariment, while its right-handed counterpart smells like caraway. 1 (R)-limonene is found in orange peels, while the (S ) enantiomer is present in lemons.2 Often, one enantiomer produces a characteristic effect, while the other either produces no effect at all, or has a totally differe ...

Synthesizing arbitrary quantum states in a superconducting resonator

... photons in a completely controlled and deterministic manner. We synthesize the states using a superconducting phase qubit to phase-coherently pump photons into the resonator, making use of an algorithm7 that generalizes a previously demonstrated method of generating photon number (Fock) states in a ...

... photons in a completely controlled and deterministic manner. We synthesize the states using a superconducting phase qubit to phase-coherently pump photons into the resonator, making use of an algorithm7 that generalizes a previously demonstrated method of generating photon number (Fock) states in a ...

Solving large eigenvalue problems in electronic structure

... Real-space Finite Difference Methods I I Use High-Order Finite Difference Methods [Fornberg & Sloan ’94] I I Typical Geometry = Cube – regular structure. I I Laplacean matrix need not even be stored. ...

... Real-space Finite Difference Methods I I Use High-Order Finite Difference Methods [Fornberg & Sloan ’94] I I Typical Geometry = Cube – regular structure. I I Laplacean matrix need not even be stored. ...

Chapter 5 | Molecular Orbitals

... Although apparently satisfactory Lewis electron-dot structures of N2, O2, and F2 can be drawn, the same is not true with Li2, Be2, B2, and C2, which violate the octet rule. In addition, the Lewis structure of O2 predicts a double-bonded, diamagnetic (all electrons paired) molecule ( O O ), but exper ...

... Although apparently satisfactory Lewis electron-dot structures of N2, O2, and F2 can be drawn, the same is not true with Li2, Be2, B2, and C2, which violate the octet rule. In addition, the Lewis structure of O2 predicts a double-bonded, diamagnetic (all electrons paired) molecule ( O O ), but exper ...

Electronic-structure calculations by first-principles

... Wesolowski, Warshal, and Weber 22 to examine a solute in solution and by Truong and co-workers to study the adsorption of water on NaCl~001!.23 Our method, discussed in subsequent sections, is related to these ideas. In the early 80’s, Whitten et al.29 developed the first cluster-in-cluster embeddin ...

... Wesolowski, Warshal, and Weber 22 to examine a solute in solution and by Truong and co-workers to study the adsorption of water on NaCl~001!.23 Our method, discussed in subsequent sections, is related to these ideas. In the early 80’s, Whitten et al.29 developed the first cluster-in-cluster embeddin ...

Resolution-of-identity approach to Hartree–Fock, hybrid

... where Ne is the number of electrons that interact via the Coulomb interaction vieej ≡ 1/|ri − r j |, and viext ≡ vext (ri ) is a local, multiplicative external potential, usually due to the nuclei. Hartree atomic units are used throughout this paper. The numerical cost for an exact solution of the H ...

... where Ne is the number of electrons that interact via the Coulomb interaction vieej ≡ 1/|ri − r j |, and viext ≡ vext (ri ) is a local, multiplicative external potential, usually due to the nuclei. Hartree atomic units are used throughout this paper. The numerical cost for an exact solution of the H ...

Reconstruction on Wigner Functions on Different

... It is well known that the wave-function of a quantum-mechanical system cannot be measured directly [12]. A single measurement does not yield enough information which allows us to determine the state of the system uniquely [12]. In addition, due to the fact that conjugated observables do not commute, ...

... It is well known that the wave-function of a quantum-mechanical system cannot be measured directly [12]. A single measurement does not yield enough information which allows us to determine the state of the system uniquely [12]. In addition, due to the fact that conjugated observables do not commute, ...

Excited states from time-dependent density functional theory

... This work focuses primarily on the linear response regime. Throughout, we emphasize the difference between small molecules (atoms, diatomics, etc.) and the larger molecules that are of greater practical interest, where TDDFT is often the only practical first-principles method. We use napthalene (C10 ...

... This work focuses primarily on the linear response regime. Throughout, we emphasize the difference between small molecules (atoms, diatomics, etc.) and the larger molecules that are of greater practical interest, where TDDFT is often the only practical first-principles method. We use napthalene (C10 ...

computational chemistry

... theory to explain the terminology used in later chapters. The core of this book is the description of the many computation techniques available and when to use them. Prioritizing which techniques work better or worse for various types of problems is a double-edged sword. This is certainly the type o ...

... theory to explain the terminology used in later chapters. The core of this book is the description of the many computation techniques available and when to use them. Prioritizing which techniques work better or worse for various types of problems is a double-edged sword. This is certainly the type o ...

THEORETICAL AND COMPUTATIONAL METHODS

... More specifically, the thesis discusses the calculation of the H+H+H three-body recombination rate coefficient using the developed method. Additionally, we discuss a conceptually simple and effective diabatization procedure for the calculation of pre-dissociated vibrational states for a system with ...

... More specifically, the thesis discusses the calculation of the H+H+H three-body recombination rate coefficient using the developed method. Additionally, we discuss a conceptually simple and effective diabatization procedure for the calculation of pre-dissociated vibrational states for a system with ...

Comparison of density functionals for energy and structural

... approach to making a HPDF, Voorhis and Scuseria28 developed a Taylor series-like density matrix expansion to obtain the so-called VSXC exchange-correlation functional29 which has 21 parameters. It is in fact a meta-GGA, since it depends not only on the density and its gradients but also on the orbit ...

... approach to making a HPDF, Voorhis and Scuseria28 developed a Taylor series-like density matrix expansion to obtain the so-called VSXC exchange-correlation functional29 which has 21 parameters. It is in fact a meta-GGA, since it depends not only on the density and its gradients but also on the orbit ...

electron-proton nonadiabaticity: characterization

... expertise and will always be grateful for the time and patience shown to me, especially when I was a younger graduate student just starting in the group. I thank her for allowing me the opportunity to work on numerous interesting projects over the years, and for continually encouraging me to explore ...

... expertise and will always be grateful for the time and patience shown to me, especially when I was a younger graduate student just starting in the group. I thank her for allowing me the opportunity to work on numerous interesting projects over the years, and for continually encouraging me to explore ...

BASIS SET SUPERPOSITION ERROR EFFECTS, EXCITED-STATE POTENTIAL ENERGY SURFACE AND

... Summary of the thesis The study of the photophysics of thymine is the main objective of this thesis. This work has been divided in 4 parts; the first two parts are devoted to find a proper level of theory for the study of thymine, whereas in the third and fourth parts the photohpysics of thymine ar ...

... Summary of the thesis The study of the photophysics of thymine is the main objective of this thesis. This work has been divided in 4 parts; the first two parts are devoted to find a proper level of theory for the study of thymine, whereas in the third and fourth parts the photohpysics of thymine ar ...

Critical thoughts on computing atom condensed Fukui functions Bultinck and Stijn Fias

... of a reacting molecule. It is thus unsurprising that many attempts are made to decompose a molecular property in to a set of atomic contributions, one for every atom A. Such atoms in molecules will henceforth be abbreviated as AIM. This is not limited to Bader’s definition44–46 but is used more gene ...

... of a reacting molecule. It is thus unsurprising that many attempts are made to decompose a molecular property in to a set of atomic contributions, one for every atom A. Such atoms in molecules will henceforth be abbreviated as AIM. This is not limited to Bader’s definition44–46 but is used more gene ...

New Concepts in Inverse Quantum Chemistry - ETH E

... In this design procedure, we rely on density functional theory (DFT), which is the only current quantum chemical theory capable of treating relatively large systems at acceptable computational cost. The fact that the accuracy of a given density functional for a particular molecular system cannot be ...

... In this design procedure, we rely on density functional theory (DFT), which is the only current quantum chemical theory capable of treating relatively large systems at acceptable computational cost. The fact that the accuracy of a given density functional for a particular molecular system cannot be ...

6 Chemical Bonding – Orbital Theory

... The orbitals containing a pair of electrons are not capable of combination. In fact, half-filled orbitals on one atom have a tendency to combine with half-filled orbitals on other atom, and the resulting orbital acquires a pair of electrons of opposite spins. (2) The atoms with valence or bonding or ...

... The orbitals containing a pair of electrons are not capable of combination. In fact, half-filled orbitals on one atom have a tendency to combine with half-filled orbitals on other atom, and the resulting orbital acquires a pair of electrons of opposite spins. (2) The atoms with valence or bonding or ...

The Random Projection Method for Hyperbolic Systems with Stiff

... time scales. This can lead to problems of numerical stiffness. Even a stable (for example, with an implicit source) scheme could lead to spurious numerical propagation speed when the reaction time scale is not properly resolved numerically. This phenomenon was first observed by Colella et al. [7], w ...

... time scales. This can lead to problems of numerical stiffness. Even a stable (for example, with an implicit source) scheme could lead to spurious numerical propagation speed when the reaction time scale is not properly resolved numerically. This phenomenon was first observed by Colella et al. [7], w ...

Tensor Product Methods and Entanglement

... The aim of the present paper is to give a pedagogical introduction to the theoretical background of this novel field and demonstrate the underlying benefits through numerical applications on a text book example. We give a technical introduction to lowrank tensor factorization and do not intend to pr ...

... The aim of the present paper is to give a pedagogical introduction to the theoretical background of this novel field and demonstrate the underlying benefits through numerical applications on a text book example. We give a technical introduction to lowrank tensor factorization and do not intend to pr ...

Explicit Polarization Theory - Comp Chem

... approximated as a Hartree product of the wave functions of the individual fragments. Consequently, the optimization of the total wave function can be reduced to the optimization of each fragment embedded in and polarized by the rest of the system. Clearly, variational optimization of the mutual depe ...

... approximated as a Hartree product of the wave functions of the individual fragments. Consequently, the optimization of the total wave function can be reduced to the optimization of each fragment embedded in and polarized by the rest of the system. Clearly, variational optimization of the mutual depe ...

Relativistic effects in atomic and molecular properties

... Until the seventies of the 20th century it was generally accepted that for a description of the electronic structure of atoms and molecules and, therefore, for the whole chemistry and for the substantial part of physics, relativistic theory is not needed. According to Sheldon L. Glashow [1], Nobel P ...

... Until the seventies of the 20th century it was generally accepted that for a description of the electronic structure of atoms and molecules and, therefore, for the whole chemistry and for the substantial part of physics, relativistic theory is not needed. According to Sheldon L. Glashow [1], Nobel P ...