{"product_id":"9783642269738","title":"Springer Theses","description":"\u003ch1\u003eSpringer Theses\u003c\/h1\u003e \u003ch2\u003eO'Regan, David D.\u003c\/h2\u003e \u003cp\u003e\u003c\/p\u003e\u003cp\u003eDensity functional theory (DFT) has become the standard workhorse for quantum mechanical simulations as it offers a good compromise between accuracy and computational cost. \u003cbr\u003eHowever, there are many important systems for which DFT performs very poorly, most notably strongly-correlated materials, resulting in a significant recent growth in interest in 'beyond DFT'  methods. The widely used  DFT+U technique, in particular, involves the addition of explicit Coulomb repulsion terms to reproduce the physics of spatially-localised electronic subspaces. \u003cbr\u003eThe magnitude of these corrective terms, measured by the famous Hubbard U parameter, has received much attention but less so for the projections used to delineate these subspaces. \u003cbr\u003e\u003cbr\u003eThe dependence on the choice of these projections is studied in detail here and a method to overcome this ambiguity in DFT+U, by self-consistently determining the projections, is introduced. \u003cbr\u003eThe author shows how nonorthogonal representations for electronic states may be used to construct these projections and, furthermore, how DFT+U may be implemented with a linearly increasing cost with respect to system size. \u003cbr\u003eThe use of nonorthogonal functions in the context of electronic structure calculations is extensively discussed and clarified, with new interpretations and results, and, on this topic, this work may serve as a reference for future workers in the field.\u003c\/p\u003e \u003ch3\u003eDetails\u003c\/h3\u003e \u003cp\u003ePublished by: Springer\u003c\/p\u003e \u003cp\u003ePublication Date: 2013-11-27\u003c\/p\u003e \u003cp\u003eFormat: Paperback\u003c\/p\u003e \u003cp\u003eISBN-13: 9783642269738\u003c\/p\u003e \u003cp\u003eDOI: 10.1007\/978-3-642-23238-1\u003c\/p\u003e \u003cp\u003eDimensions: 235cm x155cm\u003c\/p\u003e \u003cp\u003ePages: 216\u003c\/p\u003e ","brand":"Springer Berlin Heidelberg","offers":[{"title":"Default Title","offer_id":47668086243468,"sku":"9783642269738","price":98.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0710\/9545\/1788\/files\/9783642269738.jpg?v=1776461428","url":"https:\/\/lateknightbooks.com\/products\/9783642269738","provider":"Late Knight Books and Services, LLC","version":"1.0","type":"link"}