Zobrazeno 1 - 10
of 139
pro vyhledávání: '"Challacombe, Matt"'
Autor:
Challacombe, Matt
Factorization of the Gaussian RBF kernel is developed for free-mesh interpolation in the flat, polynomial limit corresponding to Taylor expansion and the Vandermonde basis of geometric moments. With this spectral approximation, a top-down octree-scop
Externí odkaz:
http://arxiv.org/abs/1511.01353
We develop the Sparse Approximate Matrix Multiply ($\tt SpAMM$) $n$-body solver for first order Newton Schulz iteration of the matrix square root and inverse square root. The solver performs recursive two-sided metric queries on a modified Cauchy-Sch
Externí odkaz:
http://arxiv.org/abs/1508.05856
We present a hybrid OpenMP/Charm++ framework for solving the $\mathcal{O} (N)$ Self-Consistent-Field eigenvalue problem with parallelism in the strong scaling regime, $P\gg{N}$, where $P$ is the number of cores, and $N$ a measure of system size, i.e.
Externí odkaz:
http://arxiv.org/abs/1403.7458
Autor:
Challacombe, Matt, Bock, Nicolas
We report an N-Body approach to computing the Fock exchange matrix with and without permutational symmetry. The method achieves an O(N lg N) computational complexity through an embedded metric-query, allowing hierarchical application of direct SCF cr
Externí odkaz:
http://arxiv.org/abs/1401.6961
Autor:
Bock, Nicolas, Challacombe, Matt
We present an optimized single-precision implementation of the Sparse Approximate Matrix Multiply (\SpAMM{}) [M. Challacombe and N. Bock, arXiv {\bf 1011.3534} (2010)], a fast algorithm for matrix-matrix multiplication for matrices with decay that ac
Externí odkaz:
http://arxiv.org/abs/1203.1692
Autor:
Challacombe, Matt, Bock, Nicolas
A fast algorithm for the approximate multiplication of matrices with decay is introduced; the Sparse Approximate Matrix Multiply (SpAMM) reduces complexity in the product space, a different approach from current methods that economize within the matr
Externí odkaz:
http://arxiv.org/abs/1011.3534
Autor:
Challacombe, Matt
A new approach to solving the Time-Dependent Self-Consistent-Field equations is developed based on the double quotient formulation of Tsiper [J. Phys. B, 34 L401 (2001)]. Dual channel, quasi-independent non-linear optimization of these quotients is f
Externí odkaz:
http://arxiv.org/abs/1001.2586
Autor:
Bock, Nicolas, Rubensson, Emanuel H., Sałek, Paweł, Niklasson, Anders M. N., Challacombe, Matt
We investigate effects of ordering in blocked matrix--matrix multiplication. We find that submatrices do not have to be stored contiguously in memory to achieve near optimal performance. Instead it is the choice of execution order of the submatrix mu
Externí odkaz:
http://arxiv.org/abs/0808.1108
Publikováno v:
J. Chem. Phys. 129, 064114 (2008)
A non-linear conjugate gradient optimization scheme is used to obtain excitation energies within the Random Phase Approximation (RPA). The solutions to the RPA eigenvalue equation are located through a variational characterization using a modified Th
Externí odkaz:
http://arxiv.org/abs/0805.3313
We present a time-reversible Born-Oppenheimer molecular dynamics scheme, based on self-consistent Hartree-Fock or density functional theory, where both the nuclear and the electronic degrees of freedom are propagated in time. We show how a time-rever
Externí odkaz:
http://arxiv.org/abs/cond-mat/0604643