Quality (philosophy)

Quantum mechanics

Catalysis

Biology

Basis (linear algebra)

Transition state

Atomic physics

Excitation

Biochemistry

Molecule

Computer science

Statistical physics

Paleontology

Physics

Organic chemistry

Mathematics

Open shell

Computational chemistry

Geometry

Series (stratigraphy)

Rotation formalisms in three dimensions

Radical

Excited state

Chemistry

Journal of Chemical Theory and Computation

Aiming at completing the sets of FCI-quality transition energies that we recently developed (J. Chem. Theory Comput. 2018, 14, 4360–4379, ibid. 2019, 15, 1939–1956, and ibid. 2020, 16, 1711–1741), we provide, in the present contribution, ultra-accurate vertical excitation energies for a series of "exotic" closed-shell molecules containing F, Cl, P, and Si atoms and small radicals, such as CON and its variants, that were not considered to date in such investigations. This represents a total of 81 high-quality transitions obtained with a series of diffuse-containing basis sets of various sizes. For the exotic compounds, these transitions are used to perform benchmarks with a vast array of lower level models, i.e., CIS(D), EOM-MP2, (SOS/SCS)-CC2, STEOM-CCSD, CCSD, CCSDR(3), CCSDT-3, (SOS-)ADC(2), and ADC(3). Additional comparisons are made with literature data. For the open-shell compounds, we compared the performance of both the unrestricted and the restricted open-shell CCSD and CC3 formalisms.

Mountaineering Strategy to Excited States: Highly Accurate Energies and Benchmarks for Exotic Molecules and Radicals