Sequences of basis sets that systematically converge towards the complete basis set (CBS) limit have been developed for the first-row transition metal elements Sc–Zn. Two families of basis sets, nonrelativistic and Douglas-Kroll-Hess (-DK) relativistic, are presented that range in quality from triple-ζ to quintuple-ζ. Separate sets are developed for the description of valence (3d4s) electron correlation (cc-pVnZ and cc-pVnZ-DK; n=T,Q, 5) and valence plus outer-core (3s3p3d4s) correlation (cc-pwCVnZ and cc-pwCVnZ-DK; n=T,Q, 5), as well as these sets augmented by additional diffuse functions for the description of negative ions and weak interactions (aug-cc-pVnZ and aug-cc-pVnZ-DK). Extensive benchmark calculations at the coupled cluster level of theory are presented for atomic excitation energies, ionization potentials, and electron affinities, as well as molecular calculations on selected hydrides (TiH, MnH, CuH) and other diatomics (TiF, Cu2). In addition to observing systematic convergence towards the C...

http://tyr0.chem.wsu.edu/~kipeters/Pages/pdfs/JCP123.064107.2005.pdf

Systematically convergent basis sets for transition metals. I. All-electron correlation consistent basis sets for the 3d elements Sc–Zn

I. Introduction and Scope 231A. Definitions of Atomic Electron Affinities 233B. Definitions of Molecular Electron Affinities 233II. Experimental Photoelectron Electron Affinities 235A. Historical Background 235B. The Photoeffect 236C. Experimental Methods 237D. Time-of-Flight Negative Ion PhotoelectronSpectroscopy239E. Some Thermochemical Uses of ElectronAffinities241F. Layout of Table 10: ExperimentalPhotoelectron Electron Affinities242III. Theoretical Determination of Electron Affinities 242A. Historical Background 2421. Theoretical Predictions of Atomic ElectronAffinities2422. Theoretical Predictions of MolecularElectron Affinities243B. Present Status of Theoretical Electron AffinityPredictions243C. Basis Sets and Theoretical Electron Affinities 244D. Density Functional Theory (DFT) andElectron Affinities245E. Layout of Tables 8 and 9: Theoretical DFTElectron Affinities247F. Details of Density Functional MethodsEmployed in Tables 8 and 9247IV. Discussion and Observations 248A. Statistical Analysis of DFT Results ThroughComparisons to Experiment and OtherTheoretical Methods248B. Theoretical EAs for Species with UnknownExperimental EAs251C. On the Applicability of DFT to Anions and theFuture of DFT EA Predictions251D. Specific Theoretical Successes 251E. Interesting Problems 2521. C

/pdf/atomic-and-molecular-electron-affinities-photoelectron-3x4vklpj6q.pdf

Atomic and molecular electron affinities: photoelectron experiments and theoretical computations.

Two new schemes for computing molecular total atomization energies (TAEs) and/or heats of formation (ΔHf∘) of first- and second-row compounds to very high accuracy are presented. The more affordable scheme, W1 (Weizmann-1) theory, yields a mean absolute error of 0.30 kcal/mol and includes only a single, molecule-independent, empirical parameter. It requires CCSD (coupled cluster with all single and double substitutions) calculations in spdf and spdfg basis sets, while CCSD(T) (i.e., CCSD with a quasiperturbative treatment of connected triple excitations) calculations are only required in spd and spdf basis sets. On workstation computers and using conventional coupled cluster algorithms, systems as large as benzene can be treated, while larger systems are feasible using direct coupled cluster methods. The more rigorous scheme, W2 (Weizmann-2) theory, contains no empirical parameters at all and yields a mean absolute error of 0.23 kcal/mol, which is lowered to 0.18 kcal/mol for molecules dominated by dynami...

Towards standard methods for benchmark quality ab initio thermochemistry :w1 and w2 theory

We propose an extension of the basis sets proposed by Ahlrichs and coworkers at Karlsruhe (these basis sets are designated as the second-generation default or “def2” basis sets in the Turbomole program). The Karlsruhe basis sets are very appealing because they constitute balanced and economical basis sets of graded quality from partially polarized double zeta to heavily polarized quadruple zeta for all elements up to radon (Z = 86). The extension consists of adding a minimal set of diffuse functions to a subset of the elements. This yields basis sets labeled minimally augmented or with “ma” as a prefix. We find that diffuse functions are not quite as important for the def2 basis sets as they are for Pople basis sets, but they are still necessary for good results on barrier heights and electron affinities. We provide assessments and validations of this extension for a variety of data sets and representative cases. We recommend the new ma-TZVP basis set for general-purpose applications of density functional theory.

Minimally augmented Karlsruhe basis sets

Experimental techniques in gas-phase ion thermochemistry.

Systematic study of the stable states of c-, si-, ge-, and sn- via infrared laser spectroscopy

Photodetachment threshold spectroscopy on the negative ions of chromium, molybdenum, copper and silver has yielded values for the electron affinities of 5451.0(10), 6027(2), 9967.2(3) and , respectively. The results agree well with previous measurements, with an improvement in the accuracy of up to a factor of 300.

https://iopscience.iop.org/article/10.1088/0953-4075/31/17/013/pdf

Infrared laser photodetachment of transition metal negative ions: studies on , , and

The electron affinity of Ir is measured to be 126174(12) ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$$\phantom{\rule{0ex}{0ex}}[156436(15)\mathrm{eV}],$ from photodetachment studies on ${\mathrm{Ir}}^{\mathrm{\ensuremath{-}}}$ Previous measurements of the electron affinity of platinum reported results which were inconsistent within quoted error bars A photodetachment study with a very improved energy resolution, signal-to-noise ratio, and signal-to-background ratio, was conducted on ${\mathrm{Pt}}^{\mathrm{\ensuremath{-}}},$ and yields a much more accurate electron affinity for Pt of 171401(4) ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ $[212510(5)\mathrm{}\mathrm{eV}],$ in good agreement with the most recent measurement Possible explanations for the poor agreement between the earlier results are discussed In both the ${\mathrm{Ir}}^{\mathrm{\ensuremath{-}}}$ and ${\mathrm{Pt}}^{\mathrm{\ensuremath{-}}}$ spectra, the data indicate that the detachment cross section deviates from the expected Wigner threshold law, even near the detachment threshold This behavior cannot be explained by the correction terms to the Wigner law proposed by the currently available threshold detachment models

Near-threshold laser spectroscopy of iridium and platinum negative ions: Electron affinities and the threshold law

An investigation of the ${\mathrm{B}}^{\ensuremath{-}}({2p}^{2}{}^{3}{P}_{J})\ensuremath{\rightarrow}\mathrm{B}(2p{}^{2}{P}_{{J}^{\ensuremath{'}}})$ photodetachment thresholds using a tunable infrared laser source has yielded a substantially improved value for the electron affinity of boron and the first experimental data on the fine structure of the ionic ground state. The $J\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0\char21{}1$ and $J\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1\char21{}2$ splittings are found to be $3.23(15){\mathrm{cm}}^{\ensuremath{-}1}$ and $5.18(15){\mathrm{cm}}^{\ensuremath{-}1}$, respectively, and the electron affinity is determined to be $2256.12(20){\mathrm{cm}}^{\ensuremath{-}1}$ [(279.723(25) meV]. The present result for the electron affinity is the first to challenge the extensive and controversial theoretical studies of this system.

Negative Ion of Boron: An Experimental Study of the 3 P Ground State

A tunable infrared laser source is utilized to study the photodetachment threshold spectra of the transition-metal negative ions ${\mathrm{Co}}^{\ensuremath{-}},$ ${\mathrm{Ni}}^{\ensuremath{-}},$ ${\mathrm{Rh}}^{\ensuremath{-}},$ and ${\mathrm{Pd}}^{\ensuremath{-}}.$ The binding energies of the respective ionic ground states are found to be 663.3(6), 1157.16(12), 1142.89(20), and 562.14(12) meV. In addition, a ${}^{3}{F}_{4}{\ensuremath{-}}^{3}{F}_{3}$ fine-structure splitting of 875(15) ${\mathrm{cm}}^{\ensuremath{-}1}$ is measured for ${\mathrm{Co}}^{\ensuremath{-}},$ and the ${}^{2}{D}_{5/2}{\ensuremath{-}}^{2}{D}_{3/2}$ splitting of ${\mathrm{Ni}}^{\ensuremath{-}}$ is determined to be 1485(3) ${\mathrm{cm}}^{\ensuremath{-}1}.$ For ${\mathrm{Pd}}^{\ensuremath{-}}$, the electronically excited ${4d}^{9}{5s}^{2}{}^{2}{D}_{5/2}$ state is found to lie 1127(4) ${\mathrm{cm}}^{\ensuremath{-}1}$ above the ${4d}^{10}{5s}^{2}{S}_{1/2}$ ionic ground state, i.e., it is bound by 422.4(5) meV. The results agree with previous values obtained from laser photodetached electron spectra, but constitute improvements in accuracy of up to two orders of magnitude.

Michael Scheer

Papers

Systematic study of the stable states of c-, si-, ge-, and sn- via infrared laser spectroscopy

Infrared laser photodetachment of transition metal negative ions: studies on , , and

Near-threshold laser spectroscopy of iridium and platinum negative ions: Electron affinities and the threshold law

Negative Ion of Boron: An Experimental Study of the 3 P Ground State

Laser spectroscopic measurements of binding energies and fine-structure splittings of co-, ni-, rh-, and pd-