Ab initio effective core potentials (ECP’s) have been generated to replace the Coulomb, exchange, and core‐orthogonality effects of the chemically inert core electron in the transition metal atoms Sc to Hg. For the second and third transition series relative ECP’s have been generated which also incorporate the mass–velocity and Darwin relativistic effects into the potential. The ab initio ECP’s should facilitate valence electron calculations on molecules containing transition‐metal atoms with accuracies approaching all‐electron calculations at a fraction of the computational cost. Analytic fits to the potentials are presented for use in multicenter integral evaluation. Gaussian orbital valence basis sets are developed for the (3d,4s,4p), (4d,5s,5p), and (5d,6s,6p) orbitals of the first, second, and third transition series atoms, respectively. All‐electron and valence‐electron atomic excitation energies are also compared for the low‐lying states of Sc–Hg, and the valence‐electron calculations are found to reproduce the all‐electron excitation energies (typically within a few tenths of an eV).

Ab initio effective core potentials for molecular calculations. Potentials for the transition metal atoms Sc to Hg

Nitrogen (N)-doped carbon materials exhibit high electrocatalytic activity for the oxygen reduction reaction (ORR), which is essential for several renewable energy systems. However, the ORR active site (or sites) is unclear, which retards further developments of high-performance catalysts. Here, we characterized the ORR active site by using newly designed graphite (highly oriented pyrolitic graphite) model catalysts with well-defined π conjugation and well-controlled doping of N species. The ORR active site is created by pyridinic N. Carbon dioxide adsorption experiments indicated that pyridinic N also creates Lewis basic sites. The specific activities per pyridinic N in the HOPG model catalysts are comparable with those of N-doped graphene powder catalysts. Thus, the ORR active sites in N-doped carbon materials are carbon atoms with Lewis basicity next to pyridinic N.

Active sites of nitrogen-doped carbon materials for oxygen reduction reaction clarified using model catalysts

Today, coupled-cluster theory offers the most accurate results among the practical ab initio electronic-structure theories applicable to moderate-sized molecules. Though it was originally proposed for problems in physics, it has seen its greatest development in chemistry, enabling an extensive range of applications to molecular structure, excited states, properties, and all kinds of spectroscopy. In this review, the essential aspects of the theory are explained and illustrated with informative numerical results.

/pdf/coupled-cluster-theory-in-quantum-chemistry-nnwxwp80ej.pdf

Coupled-cluster theory in quantum chemistry

Physical Review B

https://courses.washington.edu/cfr523/documents/Alonso2010CatalyticConversion.pdf

Catalytic conversion of biomass to biofuels

本研究では、DNAへの水和がDNAの電子状態、特に、DNA中の電荷移動に関係するフロンティア分子軌道の空間分布にどのような影響を与えるかを明らかにする目的で、中性子回折により得られた水和水を含むB型DNAに対し、密度汎関数法に基づくAb initio 分子軌道（MO）計算を行った。その結果、DNAの副溝内に水素結合する水分子に、ホール移動に関係するHOMO周辺のMOが分布することを明らかにした。従って、DNAの副溝への水分子の水素結合により、DNA中のホール移動の経路が変化する可能性がある。

https://www.jstage.jst.go.jp/article/jcac/7/0/7_0_190/_pdf

密度汎関数法による水和したｄｎａの電子状態解析： ｄｎａ副溝内の水和水がｈｏｍｏに与える影響:dna副溝内の水和水がhomoに与える影響

Collision strengths have been computed for the electron impact excitations of parity and spin forbidden transitions within the ground 1s22s22p4 manifold of Fe XIX (Fe18+). The calculations were carried out using a relativistic R-matrix close-coupling method based on the effective many-body Hamiltonian. Twenty-six target states were included in the close-coupling expansion. Effective collision strengths, assuming a Maxwellian electron velocity distribution, were evaluated for all transitions within the ground configuration. Good agreement is found with previous Breit-Pauli R-matrix calculations at low electron temperatures, 5.0 ≤ log Te ≤ 6.0 K, for all the transitions, whereas significant differences are found for electron temperatures in the range 6.0 ≤ log Te ≤ 7.0 K. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009

Effective collision strengths for electron-impact excitation of transitions within the ground 1s2 2s2 2p4 manifold of O-like Fe18+

http://ma.ecsdl.org/content/MA2009-01/2/93.full.pdf

Selective Porous Gas Sorbents for Space Life Support Systems: A Combined Experimental and Theoretical Approach

Minimum-energy structures of clusters of one sodium atom and as many as three water molecules have been calculated by combining the method of ab initio Monte Carlo simulated annealing with conventional optimization methods. 6-31G* basis sets have been employed, and each structure was optimized at the MP2 (frozen core) level of theory. © 1995 John Wiley & Sons, Inc.

Stable structures of Na(H2O)n (n = 1–3) clusters by ab initio simulated annealing

Most electronic structure calculations on molecules are done with basis sets of Gaussian type functions (GTF). Multicenter integrals over GTF are easily evaluated. However, Gaussians behave correctly at neither short nor long range; longer expansions in GTF than in exponential functions are required to attain similar accuracy. Much of the additional length is due to functions added simply to represent the region very near the nucleus. Primitive functions which represent this region may be grouped for the purpose of self-consistent field (SCF) and correlation correction procedures; the grouping is known as contraction. Contraction reduces integral storage requirements and time needed for SCF and post-SCF steps. Extensively characterized sets of contracted GTF for molecular calculations (Dunning and Hay, 1977; Wilson, 1987) exist.

Yasuyuki Ishikawa

Papers

密度汎関数法による水和したｄｎａの電子状態解析：ｄｎａ副溝内の水和水がｈｏｍｏに与える影響:dna副溝内の水和水がhomoに与える影響

Effective collision strengths for electron-impact excitation of transitions within the ground 1s2 2s2 2p4 manifold of O-like Fe18+

Selective Porous Gas Sorbents for Space Life Support Systems: A Combined Experimental and Theoretical Approach

Stable structures of Na(H2O)n (n = 1–3) clusters by ab initio simulated annealing

Accurate Relativistic Dirac-Fock and MBPT Calculations on Argon with Basis Sets of Contracted Gaussian Functions

Yasuyuki Ishikawa

Papers

密度汎関数法による水和したｄｎａの電子状態解析： ｄｎａ副溝内の水和水がｈｏｍｏに与える影響:dna副溝内の水和水がhomoに与える影響

Effective collision strengths for electron-impact excitation of transitions within the ground 1s2 2s2 2p4 manifold of O-like Fe18+

Selective Porous Gas Sorbents for Space Life Support Systems: A Combined Experimental and Theoretical Approach

Stable structures of Na(H2O)n (n = 1–3) clusters by ab initio simulated annealing

Accurate Relativistic Dirac-Fock and MBPT Calculations on Argon with Basis Sets of Contracted Gaussian Functions

密度汎関数法による水和したｄｎａの電子状態解析：ｄｎａ副溝内の水和水がｈｏｍｏに与える影響:dna副溝内の水和水がhomoに与える影響