Recently, we introduced an approach to modelling electronic structure that treats the static and dynamic components of electron correlation in different manners [1]. Static correlation is captured by a cumulant functional (CF), while dynamic correlation is captured by an on-top density functional (ODF). Such a partitioning of electron correlation between a CF and an ODF plays to the strengths of each of the related electronic structure methods. The development of a new ODF for short-range dynamic correlation [2], the extension of the method to open-shells and the treatment of double-counting of electron correlation, will be discussed.
[1] J. W. Hollett, C. Menzies and H. Hosseini, J. Chem. Phys. 145, 084106 (2016)
[2] J. W. Hollett and N. Pegoretti, J. Chem. Phys. 148, 164111 (2018)