AI Article Synopsis
- The CC-ADC method modifies the traditional polarization propagator scheme by using coupled-cluster (CC) amplitudes instead of Møller-Plesset (MP), enhancing the calculation of molecular properties like dipole polarizabilities.
- This method allows for both CC with double excitations (CCD) and single and double excitations (CCSD) to be utilized, showcasing significant improvements in results, particularly for challenging aromatic systems like benzene and pyridine.
- The new CC-ADC approaches result in better dipole polarizability calculations compared to standard methods, achieving improved accuracy at only about 1% of the computational cost of the conventional third-order method.
Article Abstract
The modification of the algebraic-diagrammatic construction (ADC) scheme for the polarization propagator using ground-state coupled-cluster (CC) instead of Møller-Plesset (MP) amplitudes, referred to as CC-ADC, is extended to the calculation of molecular properties, in particular, dipole polarizabilities. Furthermore, in addition to CC with double excitations (CCD), CC with single and double excitations (CCSD) amplitudes can be used, also in the second-order transition moments of the ADC(3/2) method. In the second-order CC-ADC(2) variants, the MP correlation coefficients occurring in ADC are replaced by either CCD or CCSD amplitudes, while in the F/CC-ADC(2) and F/CC-ADC(3/2) variants, they are replaced only in the second-order modified transition moments. These newly implemented variants are used to calculate the static dipole polarizability of several small- to medium-sized molecules, and the results are compared to the ones obtained by full configuration interaction or experiment. It is shown that the results are consistently improved by the use of CC amplitudes, in particular, for aromatic systems such as benzene or pyridine, which have proven to be difficult cases for standard ADC approaches. In this case, the second-order CC-ADC(2) and F/CC-ADC(2) variants yield significantly better results than the standard third-order ADC(3/2) method, at a computational cost amounting to only about 1% of the latter.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1063/1.5081665 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Machine Learning-Corrected Simplified Time-Dependent DFT for Systems With Inverted Single-t-o-Triplet Gaps of Interest for Photocatalytic Water Splitting.
J Comput Chem
January 2025
Department of Chemistry, University of Nevada Reno, Reno, Nevada, USA.
Hydrogen gas (H) can be produced via entirely solar-driven photocatalytic water splitting (PWS). A promising set of organic materials for facilitating PWS are the so-called inverted singlet-triplet, INVEST, materials. Inversion of the singlet (S) and triplet (T) energies reduces the population of triplet states, which are otherwise destructive under photocatalytic conditions.
View Article and Find Full Text PDFInvestigating Excited States and Absorption Spectra of the Poly-cyclopenta-dithiophene-benzothiadiazole Oligomers (Poly-CPDTBT)-A Theoretical Study.
Molecules
November 2024
The Institute of Computational Chemistry and Catalysis and Department of Chemistry, University of Girona, C/M.A. Capmany 69, 17003 Girona, Spain.
Poly-CPDTBT, as typical low-band gap copolymers, have potential applications in organic bulk heterojunction solar cells. To have a clear picture of its excited-state processes, the first task is to understand their excited states, in particular, electronic character and relevant optical absorption. Herein, the low-lying singlet excited states of Poly-CPDTBT oligomers were investigated via Algebraic Diagrammatic Construction Second Order (ADC(2)) and time-dependent density functional theory (TDDFT) method with several functionals.
View Article and Find Full Text PDFAn study on the photoisomerization in 2-styrylpyridine.
Phys Chem Chem Phys
December 2024
Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, India.
We report results of a theoretical study on photoinduced processes in 2-styrylpyridine. The geometries and the relative energies of the possible conformers were investigated using the second-order Møller-Plesset (MP2) and algebraic diagrammatic construction to second-order (ADC(2)) methods and the cc-pVTZ basis set. The complete active space self consistent field (CASSCF) method is used for locating the minimum-energy conical intersection (MECI) geometries between the S and S states.
View Article and Find Full Text PDFTheoretical insight into photodeactivation mechanisms of adenine-uracil and adenine-thymine nucleobase pairs.
Phys Chem Chem Phys
November 2024
Institute of Advanced Materials, Wroclaw University of Science and Technology, Faculty of Chemistry, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
In this work, several plausible intra- and intermolecular photoinduced processes of the Watson-Crick base pairs of adenine with uracil (A-U) or thymine (A-T) according to the results of spin component scaling variant of algebraic diagrammatic construction up to the second order [SCS-ADC(2)] calculations are discussed. Although widely explored, these systems lack complete characterization of possible intramolecular relaxation channels perturbed by intermolecular interactions. In particular, we address the still open debate on photodeactivation purine-ring puckering at the C2 or C6-atom position of adenine.
View Article and Find Full Text PDFTwo-Photon Absorption Strengths of Small Molecules: Reference CC3 Values and Benchmarks.
J Chem Theory Comput
October 2024
Nantes Université, CNRS, CEISAM UMR 6230, F-44000 Nantes, France.
We present a large dataset of highly accurate two-photon transition strengths (δ) determined for standard small molecules. Our reference values have been calculated using the quadratic response implementation of the third-order coupled cluster method including iterative triples (Q-CC3). The aug-cc-pVTZ atomic basis set is used for molecules with up to five non-hydrogen atoms, while larger molecules are assessed with aug-cc-pVDZ; the differences due to the basis sets are discussed.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!