Publications by authors named "Aniket Mandal"
Importance of Orbital Invariance in Quantifying Electron-Hole Separation and Exciton Size.
J Chem Theory Comput
November 2024
Article Synopsis
- Quantum mechanics requires that properties remain consistent regardless of how they are represented, influencing methods like density functional theory.
- Many commonly used measures of excited-state charge separation fail this requirement because they rely on incoherent averages instead of expectation values involving coherent states.
- The study suggests that replacing charge-transfer diagnostics with robust expectation values will yield more stable and physically interpretable results without increasing computational cost.
Time-dependent density functional theory (TD-DFT) within a restricted excitation space is an efficient means to compute core-level excitation energies using only a small subset of the occupied orbitals. However, core-to-valence excitation energies are significantly underestimated when standard exchange-correlation functionals are used, which is partly traceable to systemic issues with TD-DFT's description of Rydberg and charge-transfer excited states. To mitigate this, we have implemented an empirically modified combination of configuration interaction with single substitutions (CIS) based on Kohn-Sham orbitals, which is known as "DFT/CIS.
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