Messanae Universitas Studiorum: No conditions. Results ordered -Date Deposited. 2017-04-24T23:01:12ZEPrintshttp://cab.unime.it/images/sitelogo.pnghttp://cab.unime.it/mus/2012-09-25T11:06:26Z2012-09-25T11:06:26Zhttp://cab.unime.it/mus/id/eprint/780This item is in the repository with the URL: http://cab.unime.it/mus/id/eprint/7802012-09-25T11:06:26ZParallel band structure calculationsThe calculation of the electronic bands in solids can in principle easily be parallelised: the calculation of the energy bands and wave function coefficients at the various $k$ points in the Brillouin zone is independent of each other and can be done on a different processor for each $k$ point. We will illustrate this with the application of the LMTO-ASA band structure code on the Intel i-86O hypercube and also by multitasking for a Cray Y-MP. The implementation follows a master-slaves strategy where the master prepares the potential and charge densities from the wave function coefficients which are provided by the slaves. For practical applications we found it crucial not only to have compute nodes with good floating point operation characteristics, vectorising capabilities and sufficient memory, but also to have access to a fast I/O system for storage of wave function coefficients. An example is given of new possibilities in electronic structure calculations opened up by the increasing availability of parallel computer facilities. W.M. TemmermanZ. SzotekW.H. PurvisG.M. StocksA. GeistH. Winter2012-09-21T11:27:57Z2012-09-21T11:27:57Zhttp://cab.unime.it/mus/id/eprint/776This item is in the repository with the URL: http://cab.unime.it/mus/id/eprint/7762012-09-21T11:27:57ZOn the self-interaction correction to the local spin density approximationWe have implemented the self-interaction correction (SIC) to the local approximation of the density functional theory (DFT) within the linear-muffintin-orbital atomic sphere approximation (LMTO-ASA) band structure method for solids. Contrary to the application of the SIC to atoms the SIC in solids is less well founded, The magnitude of the correction depends on the degree of localization of the one-electron wave functions; i,e. a Wannier function giving rise to a larger correction than a Bloch function. So, one should minimize the total energy with respect to all possible choices of one-electron wave functions. By applying the SIC within the LMTO-ASA to systems like rare gas solids, ionic crystals and semi-core states in metals, we find that the SIC corrects at least some of the local density functional (LDF) theory deficiences and the changes are consistent with the estimates which can be made on the basis of the self-interaction corrected atomic calculations. This SIC-LDF scheme is also used to provide a better description of these materials where both localized and extended states are present, and among them, rare earth metals and Mott insulators like 3d monoxides.Z. SzotekH. WinterW.M. Temmerman