Affiliation:
1. Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry UiT The Arctic University of Norway Tromsø Norway
Abstract
AbstractA symbolic C++ library—Tinned—has been developed for symbolic differentiation and manipulation in response theory. By recognizing different key building blocks in the density matrix‐based (Thorvaldsen et al., J. Chem. Phys. 2008, 129, 214108) and coupled‐cluster response theories, we have implemented their corresponding C++ symbolic classes, including but not limited to one‐ and two‐electron operators, exchange‐correlation energy and potential, and coupled‐cluster operator. Formulas of response theory can be well expressed in terms of the symbolic classes in the library Tinned. Their high‐order perturbation‐strength derivatives can be straightforwardly computed and extracted afterwards for numerical evaluation. The library Tinned will greatly facilitate the development work of response theory and may lead to a unified framework for response theory at different levels of electronic structure theory.