TITLE

Two-electron reduced density matrices from the anti-Hermitian contracted Schrödinger equation: Enhanced energies and properties with larger basis sets

AUTHOR(S)
Mazziotti, David A.
PUB. DATE
May 2007
SOURCE
Journal of Chemical Physics;5/14/2007, Vol. 126 Issue 18, p184101
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Two-electron reduced density matrices (2-RDMs) have recently been directly determined from the solution of the anti-Hermitian contracted Schrödinger equation (ACSE) to obtain 95%–100% of the ground-state correlation energy of atoms and molecules, which significantly improves upon the accuracy of the contracted Schrödinger equation (CSE) [D. A. Mazziotti, Phys. Rev. Lett. 97, 143002 (2006)]. Two subsets of the CSE, the ACSE and the contraction of the CSE onto the one-particle space, known as the 1,3-CSE, have two important properties: (i) dependence upon only the 3-RDM and (ii) inclusion of all second-order terms when the 3-RDM is reconstructed as only a first-order functional of the 2-RDM. The error in the 1,3-CSE has an important role as a stopping criterion in solving the ACSE for the 2-RDM. Using a computationally more efficient implementation of the ACSE, the author treats a variety of molecules, including H2O, NH3, HCN, and HO3-, in larger basis sets such as correlation-consistent polarized double- and triple-zeta. The ground-state energy of neon is also calculated in a polarized quadruple-zeta basis set with extrapolation to the complete basis-set limit, and the equilibrium bond length and harmonic frequency of N2 are computed with comparison to experimental values. The author observes that increasing the basis set enhances the ability of the ACSE to capture correlation effects in ground-state energies and properties. In the triple-zeta basis set, for example, the ACSE yields energies and properties that are closer in accuracy to coupled cluster with single, double, and triple excitations than to coupled cluster with single and double excitations. In all basis sets, the computed 2-RDMs very closely satisfy known N-representability conditions.
ACCESSION #
25088213

 

Related Articles

  • Exploring degrees of entanglement. Myers, John M.; Tai Tsun Wu // Quantum Information Processing;Apr2010, Vol. 9 Issue 2, p239 

    In spite of a long history, the quantification of entanglement still calls for exploration. What matters about entanglement depends on the situation, and so presumably do the numbers suitable for its quantification. Regardless of situational complications, a necessary first step is to make...

  • Time Evolution in Macroscopic Systems. I. Equations of Motion. Grandy, Jr., W. T. // Foundations of Physics;Jan2004, Vol. 34 Issue 1, p1 

    Time evolution of macroscopic systems is re-examined primarily through further analysis and extension of the equation of motion for the density matrix ?(t). Because ? contains both classical and quantum-mechanical probabilities it is necessary to account for changes in both in the presence of...

  • The Laplacian of a Graph as a Density Matrix: A Basic Combinatorial Approach to Separability of Mixed States. Braunstein, Samuel L.; Ghosh, Sibasish; Severini, Simone // Annals of Combinatorics;2006, Vol. 10 Issue 3, p291 

    We study entanglement properties of mixed density matrices obtained from combinatorial Laplacians. This is done by introducing the notion of the density matrix of a graph. We characterize the graphs with pure density matrices and show that the density matrix of a graph can be always written as a...

  • Unified statistical method for reconstructing quantum states by purification. Bogdanov, Yu. I. // Journal of Experimental & Theoretical Physics;Jun2009, Vol. 108 Issue 6, p928 

    Mixed-state purification is used as a basis to formulate a general statistical method for reconstructing the density matrix of an arbitrary quantum state. A universal statistical distribution is obtained for the fidelity of the reconstructed quantum state. The proposed theory is supported by...

  • The Polar Decomposition And Vector Parametrization Of The Mueller Matrices. Dlugunovich, V. A.; Kurochkin, Yu. A. // AIP Conference Proceedings;3/24/2010, Vol. 1205 Issue 1, p65 

    It was demonstrated that presentation of the coherent matrix (polarization density matrix) of the electromagnetic beams as biquaternion corresponding to the four-vector of the pseudo Euclidean space with intensity and Stokes parameters as components gives the possibility for introducing of the...

  • The Accuracy of Neglecting The S-dependence and its Effect on The Exchange Parts of α-α Interaction Potential. Ismail, M. Y.; Osman, M. M.; Elgebaly, H. // Australian Journal of Basic & Applied Sciences;2011, Vol. 5 Issue 11, p120 

    The study show the effect of the local density and the accuracy of neglecting s-dependence on the exchange part of a-a interaction potential. This effect is bout 30% for the force BDM3Y2-Ried while it is less than 7% for BDM3Y1 -Reid. For BDM3Y3 force which corresponds to large value of...

  • Quantum Key Distribution Using a χ-Type State. Gao, Gan // International Journal of Theoretical Physics;Aug2010, Vol. 49 Issue 8, p1870 

    By swapping the entanglement of χ-type state, we propose a quantum key distribution protocol, in which only Alice needs to prepare χ-type states and transmit a particle sequence. Both Alice and Bob need to perform χ-type state measurements.

  • Measurable entanglement. Klyachko, Alexander; Öztop, Barıiş; Shumovsky, Alexander S. // Applied Physics Letters;3/20/2006, Vol. 88 Issue 12, p124102 

    The amount of entanglement carried by a quantum bipartite state is usually evaluated in terms of concurrence [S. Hill and W. K. Wootters, Phys. Rev. Lett. 78, 5022 (1997); P. Rungta, V. Buzˇek, C. M. Caves, M. Hillery, and G. J. Milburn, Phys. Rev. A 64, 042315 (2001)]. We give a physical...

  • Four-wave mixing in a quantum cascade laser amplifier. Friedli, Peter; Sigg, Hans; Hinkov, Borislav; Hugi, Andreas; Riedi, Sabine; Beck, Mattias; Faist, Jérôme // Applied Physics Letters;6/3/2013, Vol. 102 Issue 22, p222104 

    We present the direct observation of four-wave mixing over a detuning range of more than 3 THz in an InGaAs/AlInAs strain-compensated quantum cascade laser (QCL) amplifier emitting at 4.3 μm by simultaneous injection of a single mode QCL and a broadly tunable source. From its intensity, we...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics