Unified Framework for Molecular Response Functions of Different Electronic-Structure Models 

In short

The framework SymResponse manipulates the quasi-energy formulation of response theory at a symbolic level so that molecular response functions can be nicely represented in terms of “symbolic expressions”.

Users can further evaluate those symbolic response functions numerically by developing their own evaluation routines. The design of SymResponse makes it extensible to different electronic-structure models with only a moderate further amount of development effort. Response theory at Hartree–Fock, density functional theory, and coupled-cluster levels has been implemented in the present work, where elimination rules [Kristensen, K. J. Chem. Phys. 2008, 129, 214103] can also be applied to offer the possibility to reduce the size of computational tasks.

Publication

2025, April 16. The framework SymResponse is released as an open-source library and is available at https://github.com/bingao/symresponse: https://pubs.acs.org/doi/10.1021/acs.jpca.4c07789