The Experts below are selected from a list of 225360 Experts worldwide ranked by ideXlab platform
Ali Alavi - One of the best experts on this subject based on the ideXlab platform.
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Density matrices in full configuration interaction quantum monte carlo excited states Transition dipole moments and parallel distribution
2017Co-Authors: Nick S Blunt, George H Booth, Ali AlaviAbstract:We present developments in the calculation of reduced Density matrices (RDMs) in the full configuration interaction quantum Monte Carlo (FCIQMC) method. An efficient scheme is described to allow storage of RDMs across distributed memory, thereby allowing their calculation and storage in large basis sets. We demonstrate the calculation of RDMs for general states by using the recently introduced excited-state FCIQMC approach [N. S. Blunt et al., J. Chem. Phys. 143, 134117 (2015)] and further introduce calculation of Transition Density matrices in the method. These approaches are combined to calculate excited-state dipole and Transition dipole moments for heteronuclear diatomic molecules, including LiH, BH, and MgO, and initiator error is investigated in these quantities.
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Density matrices in full configuration interaction quantum monte carlo excited states Transition dipole moments and parallel distribution
2017Co-Authors: Nick S Blunt, George H Booth, Ali AlaviAbstract:We present developments in the calculation of reduced Density matrices (RDMs) in the full configuration interaction quantum Monte Carlo (FCIQMC) method. An efficient scheme is described to allow storage of RDMs across distributed memory, thereby allowing their calculation and storage in large basis sets. We demonstrate the calculation of RDMs for general states by using the recently-introduced excited-state FCIQMC approach [J. Chem. Phys. 143, 134117 (2015)] and further introduce calculation of Transition Density matrices (TDMs) in the method. These approaches are combined to calculate excited-state dipole and Transition dipole moments for heteronuclear diatomic molecules, including LiH, BH and MgO, and initiator error is investigated in these quantities.
Nick S Blunt - One of the best experts on this subject based on the ideXlab platform.
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Density matrices in full configuration interaction quantum monte carlo excited states Transition dipole moments and parallel distribution
2017Co-Authors: Nick S Blunt, George H Booth, Ali AlaviAbstract:We present developments in the calculation of reduced Density matrices (RDMs) in the full configuration interaction quantum Monte Carlo (FCIQMC) method. An efficient scheme is described to allow storage of RDMs across distributed memory, thereby allowing their calculation and storage in large basis sets. We demonstrate the calculation of RDMs for general states by using the recently introduced excited-state FCIQMC approach [N. S. Blunt et al., J. Chem. Phys. 143, 134117 (2015)] and further introduce calculation of Transition Density matrices in the method. These approaches are combined to calculate excited-state dipole and Transition dipole moments for heteronuclear diatomic molecules, including LiH, BH, and MgO, and initiator error is investigated in these quantities.
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Density matrices in full configuration interaction quantum monte carlo excited states Transition dipole moments and parallel distribution
2017Co-Authors: Nick S Blunt, George H Booth, Ali AlaviAbstract:We present developments in the calculation of reduced Density matrices (RDMs) in the full configuration interaction quantum Monte Carlo (FCIQMC) method. An efficient scheme is described to allow storage of RDMs across distributed memory, thereby allowing their calculation and storage in large basis sets. We demonstrate the calculation of RDMs for general states by using the recently-introduced excited-state FCIQMC approach [J. Chem. Phys. 143, 134117 (2015)] and further introduce calculation of Transition Density matrices (TDMs) in the method. These approaches are combined to calculate excited-state dipole and Transition dipole moments for heteronuclear diatomic molecules, including LiH, BH and MgO, and initiator error is investigated in these quantities.
George H Booth - One of the best experts on this subject based on the ideXlab platform.
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Density matrices in full configuration interaction quantum monte carlo excited states Transition dipole moments and parallel distribution
2017Co-Authors: Nick S Blunt, George H Booth, Ali AlaviAbstract:We present developments in the calculation of reduced Density matrices (RDMs) in the full configuration interaction quantum Monte Carlo (FCIQMC) method. An efficient scheme is described to allow storage of RDMs across distributed memory, thereby allowing their calculation and storage in large basis sets. We demonstrate the calculation of RDMs for general states by using the recently introduced excited-state FCIQMC approach [N. S. Blunt et al., J. Chem. Phys. 143, 134117 (2015)] and further introduce calculation of Transition Density matrices in the method. These approaches are combined to calculate excited-state dipole and Transition dipole moments for heteronuclear diatomic molecules, including LiH, BH, and MgO, and initiator error is investigated in these quantities.
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Density matrices in full configuration interaction quantum monte carlo excited states Transition dipole moments and parallel distribution
2017Co-Authors: Nick S Blunt, George H Booth, Ali AlaviAbstract:We present developments in the calculation of reduced Density matrices (RDMs) in the full configuration interaction quantum Monte Carlo (FCIQMC) method. An efficient scheme is described to allow storage of RDMs across distributed memory, thereby allowing their calculation and storage in large basis sets. We demonstrate the calculation of RDMs for general states by using the recently-introduced excited-state FCIQMC approach [J. Chem. Phys. 143, 134117 (2015)] and further introduce calculation of Transition Density matrices (TDMs) in the method. These approaches are combined to calculate excited-state dipole and Transition dipole moments for heteronuclear diatomic molecules, including LiH, BH and MgO, and initiator error is investigated in these quantities.
Martin T Barlow - One of the best experts on this subject based on the ideXlab platform.
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random walks on supercritical percolation clusters
2004Co-Authors: Martin T BarlowAbstract:We obtain Gaussian upper and lower bounds on the Transition Density qt(x;y) of the continuous time simple random walk on a supercritical percolation cluster C1 in the Euclidean lattice. The bounds, analogous to Aronsen's bounds for uniformly elliptic divergence form diusions, hold with constants ci depending only on p (the percolation probability) and d. The irregular nature of the medium means that the bound for qt(x; ) only holds for t Sx(!), where the constant Sx(!) depends on the percolation congura- tion !.
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random walks on supercritical percolation clusters
2003Co-Authors: Martin T BarlowAbstract:We obtain Gaussian upper and lower bounds on the Transition Density q_t(x,y) of the continuous time simple random walk on a supercritical percolation cluster C_{\infty} in the Euclidean lattice. The bounds, analogous to Aronsen's bounds for uniformly elliptic divergence form diffusions, hold with constants c_i depending only on p (the percolation probability) and d. The irregular nature of the medium means that the bound for q_t(x,\cdot) holds only for t\ge S_x(\omega), where the constant S_x(\omega) depends on the percolation configuration \omega.
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Transition Density estimates for Brownian motion on scale irregular Sierpinski gaskets
1997Co-Authors: Martin T Barlow, B.m. HamblyAbstract:Abstract We construct Brownian motion on a class of fractals which are spatially homogeneous but which do not have any exact self-similarity. We obtain Transition Density estimates for this process which are up to constants best possible.
A Schwenk - One of the best experts on this subject based on the ideXlab platform.
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equation of state and neutron star properties constrained by nuclear physics and observation
2013Co-Authors: K Hebeler, James M Lattimer, C J Pethick, A SchwenkAbstract:Microscopic calculations of neutron matter based on nuclear interactions derived from chiral effective field theory, combined with the recent observation of a 1.97 +/- 0.04 M-circle dot neutron star, constrain the equation of state of neutron-rich matter at sub-and supranuclear densities. We discuss in detail the allowed equations of state and the impact of our results on the structure of neutron stars, the crust-core Transition Density, and the nuclear symmetry energy. In particular, we show that the predicted range for neutron star radii is robust. For use in astrophysical simulations, we provide detailed numerical tables for a representative set of equations of state consistent with these constraints.
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equation of state and neutron star properties constrained by nuclear physics and observation
2013Co-Authors: K Hebeler, James M Lattimer, C J Pethick, A SchwenkAbstract:Microscopic calculations of neutron matter based on nuclear interactions derived from chiral effective field theory, combined with the recent observation of a 1.97 +- 0.04 M_sun neutron star, constrain the equation of state of neutron-rich matter at sub- and supranuclear densities. We discuss in detail the allowed equations of state and the impact of our results on the structure of neutron stars, the crust-core Transition Density, and the nuclear symmetry energy. In particular, we show that the predicted range for neutron star radii is robust. For use in astrophysical simulations, we provide detailed numerical tables for a representative set of equations of state consistent with these constraints.
