Convergence improvement for coupled cluster calculations

Convergence problems in coupled-cluster iterations are discussed, and a new iteration scheme is proposed. Whereas the Jacobi method inverts only the diagonal part of the large matrix of equation coefficients, we invert a matrix which also includes a relatively small number of off-diagonal coefficients, selected according to the excitation amplitudes undergoing the largest change in the coupled cluster iteration. A test case shows that the new IPM (inversion of partial matrix) method gives much better convergence than the straightforward Jacobi-type scheme or such well-known convergence aids as the reduced linear equations or direct inversion in iterative subspace methods.Comment: 7 pages, IOPP styl

Making sense of changing ethical expectations: The role of moral imagination

We propose that firms that engage in morally imaginative sensemaking will manage society\u27s changing ethical expectations more effectively than those engaging in habituated sensemaking. Specifically, we argue that managers engaging in habituated sensemaking will tend to view changes in expectations as threats and respond to them defensively. In contrast, morally imaginative managers will tend to see these same changes as opportunities and address them by proactively or interactively engaging stakeholders in learning processes. We contribute to the literature on moral imagination by highlighting the value of moral imagination relative to conventional sensemaking, and by positioning moral imagination as an ongoing mode of sensemaking. While we recognize that managers\u27 capacity to continuously address changing ethical expectations using moral imagination is constrained by cognitive limitations, we posit that morally imaginative sensemaking may economize on cognitive resources over time by enabling managers to avoid managing ethical issues unproductively based on habit. We also contribute to the issues management literature by calling attention to two underlying factors, managerial sensemaking mode and firm enterprise strategy, that drive companies\u27 approaches to issues management