Correlated Methods for Electronically Excited States and Open-shell Species

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Q-Chem features broad selection of correlated excited-state approaches, including equation-of-motion coupled-cluster (EOM-CC) and algebraic diagrammatic construction (ADC) families.

Features include:

  • EOM-CC methods for excited (EE), ionized/electron-attached (IP/EA), and diradical states (SF, DIP, DEA): analytic gradients, properties, interface with PCM, effective fragment potential method, and QM/MM embedding

  • ADC family of methods (EE/SF/IP/EA) including ADC(2X) and ADC(3)

  • RI-SOS-CIS(D): A wave function-based O(N4) excited-state method

  • Collinear and non-collinear SF-DFT for strongly correlated systems and conical intersections

  • Nonadiabatic and spin-orbit couplings within EOM-CC and ADC frameworks

  • Nonlinear optical properties for EOM-CC and ADC, including two-photon absorption, polarizabilities, and RIXS spectra

  • Wave-function analysis: Natural Orbitals, Natural Transition Orbitals, exciton descriptors, attachment-detachment densities, and more

  • Performance enhancements including resolution-of-identity (RI) and Cholesky decomposition, multi-core parallelization, and single-precision execution