--- res: bibo_abstract: - The transverse dynamic spin susceptibility is a correlation function that yields exact information about spin excitations in systems with a collinear magnetic ground state, including collective spin-wave modes. In an ab initio context, it may be calculated within many-body perturbation theory or time-dependent density-functional theory, but the quantitative accuracy is currently limited by the available functionals for exchange and correlation in dynamically evolving systems. To circumvent this limitation, the spin susceptibility is here alternatively formulated as the solution of an initial-value problem. In this way, the challenge of accurately describing exchange and correlation in many-electron systems is shifted to the stationary initial state, which is much better understood. The proposed scheme further requires the choice of an auxiliary basis set, which determines the speed of convergence but always allows systematic convergence in practical implementations.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Arno foaf_name: Schindlmayr, Arno foaf_surname: Schindlmayr foaf_workInfoHomepage: http://www.librecat.org/personId=458 orcid: 0000-0002-4855-071X bibo_doi: 10.1155/2018/3732892 bibo_volume: 2018 dct_date: 2018^xs_gYear dct_identifier: - UT:000422773000001 dct_isPartOf: - http://id.crossref.org/issn/1687-9120 - http://id.crossref.org/issn/1687-9139 dct_language: eng dct_publisher: Hindawi@ dct_title: Exact formulation of the transverse dynamic spin susceptibility as an initial-value problem@ ...