| 2. |
- Krogh, Jesper Wisborg, et al.
(författare)
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The condensation energy of the homogeneous superconducting gas.
- 2003
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Ingår i: Computer Physics Communications. - 0010-4655. ; 150:1, s. 53-63
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Tidskriftsartikel (refereegranskat)abstract
- We present CHS, a computer program designed to calculate the condensation energy of the homogeneous superconducting electron gas. The correlation energy, which we treat at the level of the RPA, is an essential ingredient for the construction of a local density approximation in the framework of density functional theory for superconductors (SCDFT) [Kurth et al., Phys. Rev. Lett. 83 (1999) 2628].
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| 3. |
- Lindh, Roland, 1958-, et al.
(författare)
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Semidirect parallel self-consistent field : the load balancing problem in the input/output intensive self-consistent field iterations
- 2003
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Ingår i: Theoretical Chemistry accounts. - : Springer Science and Business Media LLC. - 1432-881X .- 1432-2234. ; 110:3, s. 156-164
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Tidskriftsartikel (refereegranskat)abstract
- The full capacity of contemporary parallel computers can, in the context of iterative ab initio procedures like, for example, self-consistent field (SCF) and multiconfigurational SCF, only be utilized if the disk and input/output (I/O) capacity are fully exploited before the implementation turns to an integral direct strategy. In a recent report on parallel semidirect SCF http://www.tc.cornell.edu/er/media/1996/collabrate.html, http://www.fp.mcs.anl.gd/grand-challenges/chem/non-direct/index.html it was demonstrated that super-linear speedups are achievable for algorithms that exploit scalable parallel I/O. In the I/O-intensive SCF iterations of this implementation a static load balancing, however, was employed, dictated by the initial iteration in which integral evaluation dominates the central processing unit activity and thus determines the load balancing. In the present paper we present the first implementation in which load balancing is achieved throughout the whole SCF procedure, i.e. also in subsequent iterations. The improved scalability of our new algorithm is demonstrated in some test calculations, for example, for 63-node calculation a speedup of 104 was observed in the computation of the two-electron integral contribution to the Fock matrix.
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