The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform

Herbert A. Hauptman - One of the best experts on this subject based on the ideXlab platform.

  • TELS : least-squares solution of the structure-invariant equations
    Acta Crystallographica Section A Foundations of Crystallography, 1991
    Co-Authors: F. Han, George T. Detitta, Herbert A. Hauptman
    Abstract:

    Procedures are described to extract the values of individual phases from estimated structure invariants. The linear-equation and least-squares methods are used as two separate techniques in these procedures. The linear-equation method uses a Linearly Independent Set of equations, with arbitrarily assigned integers, which are sufficient in number to solve for values of an equal number of phases. The least-squares method uses a Set of overdetermined equations in which an `integer problem' has to be considered. The assembly of these two techniques with a novel integer-trial-and-error method shows a remarkable ability to overcome the `integer problem'. As a test of the whole procedure, phases were extracted from three-phase structure invariants calculated from the theoretical data for the platinum chloride derivative of cytochrome c550.

Gustavo E. Scuseria - One of the best experts on this subject based on the ideXlab platform.

  • Construction of Linearly Independent non-orthogonal AGP states
    The Journal of chemical physics, 2021
    Co-Authors: Rishab Dutta, Guo P. Chen, Thomas M. Henderson, Gustavo E. Scuseria
    Abstract:

    We show how to construct a Linearly Independent Set of antisymmetrized geminal power (AGP) states, which allows us to rewrite our recently introduced geminal replacement models as linear combinations of non-orthogonal AGPs. This greatly simplifies the evaluation of matrix elements and permits us to introduce an AGP-based selective configuration interaction method, which can reach arbitrary excitation levels relative to a reference AGP, balancing accuracy and cost as we see fit.

Anthony Chefles - One of the best experts on this subject based on the ideXlab platform.

  • Unambiguous discrimination between Linearly dependent states with multiple copies
    Physical Review A, 2001
    Co-Authors: Anthony Chefles
    Abstract:

    A Set of quantum states can be unambiguously discriminated if and only if they are Linearly Independent. However, for a Linearly dependent Set, if C copies of the state are available, then the resulting C particle states may form a Linearly Independent Set, and be amenable to unambiguous discrimination. We obtain one necessary and one sufficient condition for the possibility of unambiguous discrimination among N states given that C copies are available and that the single copies span a D-dimensional space. These conditions are found to be identical for qubits. We then examine in detail the Linearly dependent trine ensemble. The Set of $Cg1$ copies of each state is a Set of Linearly Independent lifted trine states. The maximum unambiguous discrimination probability is evaluated for all $Cg1$ with equal a priori probabilities.

  • Deterministic quantum state transformations
    Physics Letters A, 2000
    Co-Authors: Anthony Chefles
    Abstract:

    Abstract We derive necessary conditions for the existence of a completely positive, linear, trace-preserving map which deterministically transforms one finite Set of pure quantum states into another. These conditions are also sufficient for Linearly Independent initial states. We also examine the issue of quantum coherence, that is, when such operations maintain the purity of superpositions. If, under any deterministic transformation from one Linearly Independent Set to another, even a single complete superposition maintains its purity, then the initial and final states are related by a unitary transformation.

F. Han - One of the best experts on this subject based on the ideXlab platform.

  • TELS : least-squares solution of the structure-invariant equations
    Acta Crystallographica Section A Foundations of Crystallography, 1991
    Co-Authors: F. Han, George T. Detitta, Herbert A. Hauptman
    Abstract:

    Procedures are described to extract the values of individual phases from estimated structure invariants. The linear-equation and least-squares methods are used as two separate techniques in these procedures. The linear-equation method uses a Linearly Independent Set of equations, with arbitrarily assigned integers, which are sufficient in number to solve for values of an equal number of phases. The least-squares method uses a Set of overdetermined equations in which an `integer problem' has to be considered. The assembly of these two techniques with a novel integer-trial-and-error method shows a remarkable ability to overcome the `integer problem'. As a test of the whole procedure, phases were extracted from three-phase structure invariants calculated from the theoretical data for the platinum chloride derivative of cytochrome c550.

Rishab Dutta - One of the best experts on this subject based on the ideXlab platform.

  • Construction of Linearly Independent non-orthogonal AGP states
    The Journal of chemical physics, 2021
    Co-Authors: Rishab Dutta, Guo P. Chen, Thomas M. Henderson, Gustavo E. Scuseria
    Abstract:

    We show how to construct a Linearly Independent Set of antisymmetrized geminal power (AGP) states, which allows us to rewrite our recently introduced geminal replacement models as linear combinations of non-orthogonal AGPs. This greatly simplifies the evaluation of matrix elements and permits us to introduce an AGP-based selective configuration interaction method, which can reach arbitrary excitation levels relative to a reference AGP, balancing accuracy and cost as we see fit.