Messanae Universitas Studiorum: No conditions. Results ordered -Date Deposited. 2019-08-24T05:55:20ZEPrintshttp://cab.unime.it/images/sitelogo.pnghttp://cab.unime.it/mus/2014-04-17T09:53:16Z2014-04-17T09:53:16Zhttp://cab.unime.it/mus/id/eprint/5168This item is in the repository with the URL: http://cab.unime.it/mus/id/eprint/51682014-04-17T09:53:16ZOn the electronic structure of ordered and substitutional disordered Fe-Al and Fe-Al-Ti alloysWe present first principle total energy KKR-CPA calculations (1)of $Fe_0_._5- Al_0_._5$ and $Fe_0_._4_7_5- Al_0_._4_7_5-Ti_0_.0_5$ alloys, both in the ordered and random crystal structure. We found that the ordered B2 crystal structure is always more stable with respect to the random alloys. This behaviour is discussed in terms of the electronic structure. The last is characterized by almost orizontal Fe d bands at the Fermi energy. The disorder induced broadening of these states does not allow the definition of a neat Fermi surface in the random phases(2). The addition of Ti does not change qualitatively the energetic behaviour of the systems. We found however a remarkable energy shift between Ti d states on different sublattices of the B2 structure. P. DonatoG. M. FlorioB. GinatempoE. BrunoE. S. Giuliano2012-09-21T11:44:31Z2012-09-21T11:44:31Zhttp://cab.unime.it/mus/id/eprint/779This item is in the repository with the URL: http://cab.unime.it/mus/id/eprint/7792012-09-21T11:44:31ZA high performance code to calculate the electronic properties of metals and alloysWe report on an application code for the $ab initio$ calculation of electronic properties of multicomponent ordered and disordered solids. This code was awarded of the 1990 Gordon Bell Prize for the price/performance ratio. We briefly describe the multiple scattering based algorithm (KKR-CPA) underlying the code and analyse the reasons why this theory is computationally expensive but can be coded to exploit either distributed or shared memory supercomputers. Experimental runs on Intel iPSC/860, CRAY-YMP and other machines are presented and their performances compared. Furthermore both relativistic and non-relativistic applications on $N_i_0_._5 — Pt_0_._5$ alloy are presented together with a discussion of the interplay of disorder, relativity, and charge selfconsistency. B. GinatempoG.A. GeistG.M. StocksW.A. SheltonE. Bruno2012-09-21T11:35:38Z2013-04-04T07:33:49Zhttp://cab.unime.it/mus/id/eprint/778This item is in the repository with the URL: http://cab.unime.it/mus/id/eprint/7782012-09-21T11:35:38ZFast numerical solution of kkr-cpa equation:new algorithms for self-consistent-field calculationsSome numerical methods for the solution of KKR-CPA equations are discussed and tested. New, efficent, computational algorithms are proposed, allowing a remarkable reduction of computing time. The application of this computational scheine to self-consistent-field calculation is also discussed.
E. BrunoG. M. FlorioB. GinatempoE. S. Giuliano