400 research outputs found
Integral-Direct and Parallel Implementation of the CCSD(T) Method: Algorithmic Developments and Large-Scale Applications
Digitally Implemented Naturally Sampled SVM Applied in Speed Sensor-less Field Oriented Controlled Induction Motor Drive
A generalized skew information and uncertainty relation
A generalized skew information is defined and a generalized uncertainty
relation is established with the help of a trace inequality which was recently
proven by J.I.Fujii. In addition, we prove the trace inequality conjectured by
S.Luo and Z.Zhang. Finally we point out that Theorem 1 in {\it S.Luo and
Q.Zhang, IEEE Trans.IT, Vol.50, pp.1778-1782 (2004)} is incorrect in general,
by giving a simple counter-example.Comment: to appear in IEEE TI
Approaching the Basis Set Limit of CCSD(T) Energies for Large Molecules with Local Natural Orbital Coupled-Cluster Methods
Novel orthogonalization and biorthogonalization algorithms - Towards multistate multiconfiguration perturbation theory
Orthogonalization with the prerequisite of keeping several vectors
fixed is examined. Explicit formulae are derived both for
orthogonal and biorthogonal vector sets. Calculation
of the inverse or square root of the entire overlap
matrix is eliminated, allowing computational time reduction.
In this special situation it is found sufficient to evaluate
functions of matrices of the dimension matching the
number of fixed vectors.
The (bi)orthogonal sets find direct application in
extending multiconfigurational perturbation theory
to deal with multiple reference vectors
Development of e-Learning Modules for Teaching Energy for Sustainable World
Within the project ”Teaching Energy for
Sustainable World” (SustEner) financed by the
European Union nine practically oriented modules with
remote experiments or interactive animation materials
will be offered in a web based learning portal. Here the
development and the operation of two modules titled
”Solar Powered Electric Vehicles” and ”Luminous
Efficacy of Modern Light Sources” are described in
some detail
Reduced-scaling correlation methods for the excited states of large molecules: implementation and benchmarks for the second-order algebraic-diagrammatic construction approach
A framework for the reduced-scaling implementation of excited-state correlation methods is presented. An algorithm is introduced to construct excitation-specific local domains, which include all the important molecular orbitals for the excitation as well as for the electron correlation. The orbital space dimensions of the resulting compact domains are further decreased utilizing our reduced-cost techniques developed previously [J. Chem. Phys. 148, 094111 (2018)] based on the natural auxiliary function and local natural orbital approaches. Additional methodological improvements for the evaluation of density matrices are also discussed. Benchmark calculations are presented at the second-order algebraic-diagrammatic construction level. Compared to our reduced-cost algorithm significant, up to 3-9-fold speedups are achieved even for systems of smaller than 100 atoms. At the same time the additional errors introduced by the domain approximations are highly acceptable being about 2-4 meV on the average. The presented reduced-scaling algorithm allows us to carry out correlated excited-state calculations using triple-zeta basis sets with diffuse functions for systems of up to 400 atoms or 13000 atomic orbitals in a matter of days using an 8-core processor
Reduced-cost second-order algebraic-diagrammatic construction method for excitation energies and transition moments
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