Dataset Information

Correlation Consistent Basis Sets and Core Polarization Potentials for Al-Ar with ccECP Pseudopotentials.

ABSTRACT: New correlation consistent basis sets for the second-row atoms (Al-Ar) to be used with the neon-core correlation consistent effective core potentials (ccECPs) have been developed. The basis sets, denoted cc-pV(n+d)Z-ccECP (n = D, T, Q), include the "tight"-d functions that are known to be important for second-row elements. Sets augmented with additional diffuse functions are also reported. Effective core polarization potentials (CPPs) to account for the effect of core-valence correlation have been adjusted for the same elements, and two different forms of the CPP cutoff function have been analyzed. The accuracy of both the basis sets and the CPPs is assessed through benchmark calculations at the coupled-cluster level of theory for atomic and molecular properties. Agreement with all-electron results is much improved relative to the basis sets that originally accompanied the ccECPs; moreover, the combination of cc-pV(n+d)Z-ccECP and CPPs is found to be a computationally efficient and accurate alternative to including core electrons in the correlation treatment.

SUBMITTER: Hill AN

PROVIDER: S-EPMC9442647 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Correlation Consistent Basis Sets and Core Polarization Potentials for Al-Ar with ccECP Pseudopotentials.

Hill Adam N AN Meijer Anthony J H M AJHM Hill J Grant JG

The journal of physical chemistry. A 20220817 34

New correlation consistent basis sets for the second-row atoms (Al-Ar) to be used with the neon-core correlation consistent effective core potentials (ccECPs) have been developed. The basis sets, denoted cc-pV(<i>n</i>+d)Z-ccECP (<i>n</i> = D, T, Q), include the "tight"-d functions that are known to be important for second-row elements. Sets augmented with additional diffuse functions are also reported. Effective core polarization potentials (CPPs) to account for the effect of core-valence corre ...[more]

PMID: 35976118

Similar Datasets

Project description:Second-order Møller-Plesset perturbation theory (MP2) is the most expedient wave function-based method for considering electron correlation in quantum chemical calculations and, as such, provides a cost-effective framework to assess the effects of basis sets on correlation energies, for which the complete basis set (CBS) limit can commonly only be obtained via extrapolation techniques. Software packages providing MP2 energies are commonly based on atom-centered bases with innate issues related to possible basis set superposition errors (BSSE), especially in the case of weakly bonded systems. Here, we present noncovalent interaction energies in the CBS limit, free of BSSE, for 20 dimer systems of the S22 data set obtained via a highly parallelized MP2 implementation in the plane-wave pseudopotential molecular dynamics package CPMD. The specificities related to plane waves for accurate and efficient calculations of gas-phase energies are discussed, and results are compared to the localized (aug-)cc-pV[D,T,Q,5]Z correlation-consistent bases as well as their extrapolated CBS estimates. We find that the BSSE-corrected aug-cc-pV5Z basis can provide MP2 energies highly consistent with the CBS plane wave values with a minimum mean absolute deviation of ∼0.05 kcal/mol without the application of any extrapolation scheme. In addition, we tested the performance of 13 different extrapolation schemes and found that the X-3 expression applied to the (aug-)cc-pVXZ bases provides the smallest deviations against CBS plane wave values if the extrapolation sequence is composed of points D and T, while (X+12)-4 performs slightly better for TQ and Q5 extrapolations. Also, we propose A(X-12)-3+B(X+12)-4 as a reliable alternative to extrapolate total energies from the DTQ, TQ5, or DTQ5 data points. In spite of the general good agreement between the values obtained from the two types of basis sets, it is noticed that differences between plane waves and (aug-)cc-pVXZ basis sets, extrapolated or not, tend to increase with the number of electrons, thus raising the question of whether these discrepancies could indeed limit the attainable accuracy for localized bases in the limit of large systems.

Project description:We illustrate control of a polarized laser optical trapping potential landscape through the nonideal mixing of binary liquids. The inherent trapping potential asymmetry (ITPA) present in the trapping region results from the asymmetric intensity distribution in focal volume due to the high numerical aperture objective lens. Experimentally, we show that this ITPA effect can be modified and/or removed by the use of binary liquid mixtures. From our femtosecond optical tweezers experiments, we determine the topograph of the trapping potential base on the fluctuation-dissipation theorem. Additionally, the Brownian motion of the trapped bead is sensitive to the frictional force (FF) of the surroundings that is exerted by clusters of water and alcohol binary mixture through extended hydrogen bonding. Thus, using these two effects, ITPA and FF of the medium, we have shown that one can indeed modify the effective trapping potential landscape. Water-alcohol binary mixtures display a nonlinear dependence on the microrheological properties of the solvent composition as a result of rigid cluster formation. Volumetrically, at about 30% methanol in water binary mixture, the trapping asymmetry is minimal. In this particular binary mixture composition, the hydrophobic part of the methanol molecule is surrounded by 'cages' of water molecules. Enhanced H-bonding network of water molecules results in higher viscosity, which contributes to the higher frictional force. Increased viscosity decreases the degree of anisotropy due to hindered dipolar rotation. However, at higher methanol concentrations, the methanol molecules are no longer contained within the water cages and are free to move, which decrease their overall bulk viscosity. Thus, for pure solvents, experimentally measured anisotropy matches quite well with the theoretical prediction, but this fails in case of the binary mixtures due to the increased frictional force exerted by binary mixtures that result from the formation of cage-like structures.

Dataset Information

Correlation Consistent Basis Sets and Core Polarization Potentials for Al-Ar with ccECP Pseudopotentials.

Publications

Correlation Consistent Basis Sets and Core Polarization Potentials for Al-Ar with ccECP Pseudopotentials.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets