Electronic Structure Calculations of the Copper Oxygen Planes in Yba2Cu3O6+δ, for 0 < δ < 1

1989 ◽  
Vol 169 ◽  
Author(s):  
J. A. Cogordan
Keyword(s):  
Electronic Structure ◽  
Excited State ◽  
Ab Initio ◽  
Molecular Orbital ◽  
Lower Energy ◽  
Closed Shell ◽  
Electronic Structure Calculations ◽  
Open Shell ◽  
Molecular Orbitals ◽  
Structure Calculations

AbstractMolecular ab initio seIf-consistent calculations on clusters simulating the copper-oxygen layers in the Yba2Cu3O6;δ are reported. The electronic structure, of this layer, was computed for different sets of values of the lattice parameters (a,b,c), according to their dependence on the oxygen stiochiometry. For the molecular orbitals , two different electronic occupations are considered, a closed shell and an open shell. For the open shell, an electron has been excited to the first virtual molecular orbital. It is found that this excited state has lower energy than the closed shell configuration for 0 < δ < 1. Molecular energies an electronic population are reported.

Electronic Structure Calculations on a Real-Space Mesh with Multigrid Acceleration

1995 ◽  
Vol 408 ◽  
Author(s):  
D. J. Sullivan ◽  
E. L. Briggs ◽  
C. J. Brabec ◽  
J. Bernholc
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Large Scale ◽  
Electronic Structure Calculations ◽  
High Energy ◽  
Real Space ◽  
Parallel Architectures ◽  
Wurtzite Phase ◽  
Ongoing Work ◽  
Structure Calculations

AbstractWe have developed a set of techniques for performing large scale ab initio calculations using multigrid accelerations and a real-space grid as a basis. The multigrid methods permit efficient calculations on ill-conditioned systems with long length scales or high energy cutoffs. We discuss the design of pseudopotentials for real-space grids, and the computation of ionic forces. The technique has been applied to several systems, including an isolated C60 molecule, the wurtzite phase of GaN, a 64-atom cell of GaN with the Ga d-states in valence, and a 443-atom protein. The method has been implemented on both vector and parallel architectures. We also discuss ongoing work on O(N) implementations and solvated biomolecules.

scholarly journals LOCALLY PROJECTED MOLECULAR ORBITAL THEORY FOR MOLECULAR INTERACTION WITH A HIGH-SPIN OPEN-SHELL MOLECULE

2006 ◽  
Vol 05 (04) ◽  
pp. 819-833 ◽  
Author(s):  
SUEHIRO IWATA
Keyword(s):  
Molecular Orbital ◽  
High Spin ◽  
Closed Shell ◽  
Open Shell ◽  
Coefficient Matrix ◽  
Molecular Orbitals ◽  
Orbital Method ◽  
Stationary Condition ◽  
Orbital Theory ◽  
Stationary Conditions

Locally projected molecular orbital method for molecular interactions is extended to a cluster consisting of a high-spin open-shell molecule and many closed-shell molecules. While deriving the equations, the Hartee–Fock–Roothaan equation without the orthonormal condition is obtained. The stationary conditions for molecular orbitals are expressed in a form of a generalized Brillouin condition. To obtain the molecular orbital coefficient matrix, which satisfies the stationary condition, a single Fock operator form is presented. For the locally projected molecular orbitals for the open-shell cluster, the working matrix representaion is given.

Electronic structure calculations and nonadiabatic dynamics simulations of excited-state relaxation of Pigment Yellow 101

2018 ◽  
Vol 20 (9) ◽  
pp. 6524-6532 ◽  
Author(s):  
Meng Che ◽  
Yuan-Jun Gao ◽  
Yan Zhang ◽  
Shu-Hua Xia ◽  
Ganglong Cui
Keyword(s):  
Electronic Structure ◽  
Excited State ◽  
Electronic Structure Calculations ◽  
Nonadiabatic Dynamics ◽  
Dynamics Simulations ◽  
Structure Calculations

Pigment Yellow 101 (PY101) is widely used as a typical pigment due to its excellent excited-state properties.

Summary, Conclusions, and Future Trends

2012 ◽  
Author(s):  
Lionel Raff ◽  
Ranga Komanduri ◽  
Martin Hagan ◽  
Satish Bukkapatnam
Keyword(s):  
Electronic Structure ◽  
Complex Systems ◽  
Human Brain ◽  
Ab Initio ◽  
Large Scale ◽  
Dimensional Space ◽  
Electronic Structure Calculations ◽  
Potential Surfaces ◽  
The 1960S ◽  
Structure Calculations

Since the introduction of classical and semiclassical molecular dynamics (MD) methods in the 1960s and Gaussian procedures to conduct electronic structure calculations in the 1970s, a principal objective of theoretical chemistry has been to combine the two methods so that MD and quantum mechanical studies can be conducted on ab initio potential surfaces. Although numerous procedures have been attempted, the goal of first principles, ab initio dynamics calculations has proven to be elusive when the system contains five or more atoms moving in unrestricted three-dimensional space. For many years, the conventional wisdom has been that ab initio MD calculations for complex systems containing five or more atoms with several open reaction channels are presently beyond our computational capabilities. The rationale for this view are (a) the inherent difficulty of high level ab initio quantum calculations on complex systems that may take numerous, large-scale computations impossible, (b) the large dimensionality of the configuration space for such systems that makes it necessary to examine prohibitively large numbers of nuclear configurations, and (c) the extreme difficulty associated with obtaining sufficiently converged results to permit accurate interpolation of numerical data obtained from electronic structure calculations when the dimensionality of the system is nine or greater. Neural networks (NN) derive their name from the fact that their interlocking structure superficially resembles the neural network of a human brain and from the fact that NNs can sense the underlying correlations that exist in a database and properly map them in a manner analogous to the way a human brain can execute pattern recognition. Artificial neurons were first proposed in 1943 by Warren McCulloch, a neurophysiologist, and Walter Pitts, an MIT logician. NNs have been employed by engineers for decades to assist in the solution of a multitude of problems. Nevertheless, the power of NNs to assist in the solution of numerous problems that occur in chemical reaction dynamics is just now being realized by the chemistry community.

scholarly journals The 3s versus 3p Rydberg state photodissociation dynamics of the ethyl radical

2019 ◽  
Vol 21 (41) ◽  
pp. 23017-23025 ◽  
Author(s):  
Sonia Marggi Poullain ◽  
David V. Chicharro ◽  
Alexandre Zanchet ◽  
Luis Rubio-Lago ◽  
Alberto García-Vela ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Rydberg State ◽  
Rydberg States ◽  
Electronic Structure Calculations ◽  
Velocity Map Imaging ◽  
Ethyl Radical ◽  
Structure Calculations

Photodissociation dynamics of the ethyl radical from the 3s vs. 3p Rydberg states studied by velocity map imaging and ab initio electronic structure calculations.

Mechanisms of photoreactivity in hydrogen-bonded adenine–H2O complexes

2019 ◽  
Vol 21 (26) ◽  
pp. 14238-14249 ◽  
Author(s):  
Xiuxiu Wu ◽  
Johannes Ehrmaier ◽  
Andrzej L. Sobolewski ◽  
Tolga N. V. Karsili ◽  
Wolfgang Domcke
Keyword(s):  
Wave Function ◽  
Electronic Structure ◽  
Ab Initio ◽  
Electronic Structure Calculations ◽  
Water Molecules ◽  
Photoinduced Reactions ◽  
Structure Calculations ◽  
Hydrogen Bonded

The mechanisms of photoinduced reactions of adenine with water molecules in hydrogen-bonded adenine–water complexes were investigated with ab initio wave-function-based electronic-structure calculations.

Sign in / Sign up

Export Citation Format

Share Document