Optimization of inhomogeneous electron correlation factors in periodic solids

A method is presented for the optimization of one-body and inhomogeneous two-body terms in correlated electronic wave functions of Jastrow-Slater type. The most general form of inhomogeneous correlation term which is compatible with crystal symmetry is used and the energy is minimized with respect to all parameters using a rapidly convergent iterative approach, based on Monte Carlo sampling of the energy and fitting energy fluctuations. The energy minimization is performed exactly within statistical sampling error for the energy derivatives and the resulting one- and two-body terms of the wave function are found to be well-determined. The largest calculations performed require the optimization of over 3000 parameters. The inhomogeneous two-electron correlation terms are calculated for diamond and rhombohedral graphite. The optimal terms in diamond are found to be approximately homogeneous and isotropic over all ranges of electron separation, but exhibit some inhomogeneity at short- and intermediate-range, whereas those in graphite are found to be homogeneous at short-range, but inhomogeneous and anisotropic at intermediate- and long-range electron separation.Comment: 23 pages, 15 figures, 1 table, REVTeX4, submitted to PR

Evolving priorities in sponsorship:from media management to network management

Commercial sponsorship has continually adapted to the needs of the market. The purpose of this paper is to tracks these changes and draw out the evolution in management capabilities required to manage sponsorship effectively. Five distinct approaches to sponsorship have been identified from an extensive review of the literature, including: the philanthropic approach, the market-centred approach, the consumer-centred approach, the strategic resource, and finally the relations and networks approach. By examining these approaches, the paper identifies key capabilities required for the future of sponsorship, including network visioning, network orchestration, and relationship portfolio management. This is presented in a four-level framework for sponsorship network management. This paper serves two key audiences. On the one hand, for sponsorship managers, it examines past and future capabilities required to manage sponsorship effectively. For researchers, the paper historically reviews the emergence of sponsorship capabilities and sets out a research agenda to progress our understanding on a network perspective on sponsorship