The stabilization method is used in conjunction with Koopmans-based approximation to calculate the energies of pi* temporary anion states of a series of substituted benzenes in density functional theory. In this approach, the Koopmans expression is corrected due to the consideration of the integer discontinuities in the exact exchange-correlation potential. Stabilization is accomplished by varying the exponents of appropriate diffuse functions. The energies of pi* states are then identified by investigating the relationship between the resultant eigenvalues and scale parameter. Results indicate that this approach can yield an improvement in the predictions of the absolute energies of pi* states over other methods.

In this paper, density functional theory is used to investigate (benzene)chromium tricarbonyl, (cyclopentadienyl)manganese tricarbonyl, (1,3-butadiene)iron tricarbonyl, and (cyclopentadienyl)cobalt dicarbonyl. For the energies of low-lying temporary anion states, the stabilized Koopmans-based (S-KB) and stabilized Koopmans theorem (S-KT) methods are adopted. Stabilization is accomplished by varying the exponents of appropriate diffuse functions. Results indicate that the calculations of S-KB using PBEPBE and S-KT using CAM-B3LYP are able to yield energies of temporary anion states in good agreement with the experimental values. Furthermore, the ionization potentials can be determined accurately via the Koopmans-based (KB) PBEPBE method.

In this paper, density functional theory (DFT) with asymptotically corrected potentials is used to investigate CH(3)CN, CH(3)NC, CH(3)SCN, and CH(3)NCS molecules. For the energies of σ* and π* temporary anion states, the stabilized Koopmans' theorem (S-KT) using long-range correction functional and stabilized Koopmans-based (S-KB) approximation using local functional, are adopted. The stabilization procedure is accomplished by varying the exponents of appropriate diffuse functions. Results indicate that the calculations based on asymptotically corrected density functionals can yield better energy results of temporary anion states over conventional DFT methods.

The Koopmans-based (KB) approximation is used to investigate the ionization potentials of ferrocene and dibenzene chromium in density functional theory. As to the energies of low-lying temporary anion states of these transition metal complexes, the stabilization method coupled with KB approximation (S-KB) is adopted. Here, the stabilization is accomplished by varying the exponents of appropriate diffuse functions. Results indicate that the S-KB method is much more successful than other methods in predicting absolute and relative energies of temporary anion states. Furthermore, the ionization potentials via KB approach are very close to the experimental values.

Selection of appropriate genetic markers to quantify phylogenetic diversity is crucial for community ecology studies. Yet, systematic evaluation of marker genes for this purpose is scarcely done. Recently, the combined effort of phycologists has produced a rich plastid genome resource with taxonomic representation spanning all of the major lineages of the red algae (Rhodophyta). In this proof‐of‐concept study, we leveraged this resource by developing and applying a phylogenomic strategy to seek candidate plastid markers suitable for phylogenetic community analysis. We ranked the core genes of 107 published plastid genomes based on various sequence‐derived properties and their tree distance to plastid genome phylogenies. The resulting ranking revealed that the most widely used marker, rbcL, is not necessarily the optimal marker, while other promising markers might have been overlooked. We designed and tested PCR primers for several candidate marker genes, and successfully amplified one of them, rpoC1, in a taxonomically broad set of red algal specimens. We suggest that our general marker identification methodology and the rpoC1 primers will be useful to the phycological community for investigating the biodiversity and community ecology of the red algae.