New massively parallel linear-response coupled-cluster module in ACES III: application to static polarisabilities of closed-shell molecules and oligomers and of open-shell radicals

ABSTRACT

Stemming from our implementation of parallel coupled-cluster (CC) capabilities for electron spin resonance properties [J. Chem. Phys. 139, 174103 (2013)], we present a new massively parallel linear response CC module within ACES III. Unlike alternative parallel CC modules, this general purpose module evaluates any type of first- and second-order CC properties of both closed- and open-shell molecules employing restricted, unrestricted and restricted-open-shell Hartree–Fock (HF) references. We demonstrate the accuracy and usefulness of this module through the calculation of static polarisabilities of large molecules. Closed-shell calculations are performed at the following levels: second-order many-body perturbation theory [MBPT(2)], CC with single- and double-excitations (CCSD), coupled-perturbed HF and density functional theory (DFT), and open-shell calculations at the unrestricted CCSD (UCSSD) one. Applications involve eight closed-shell organic-chemistry molecules (Set I), the first four members of the closed-shell thiophene oligomer series (Set II), and five open-shell radicals (Set III). In Set I, all calculated average polarisabilities agree reasonably well with experimental data. In Set II, all calculated average polarisabilities vs. the number of monomers show comparable values and saturation patterns and demonstrate that experimental polarisabilities may be inaccurate. In Set III, UCCSD perpendicular polarisabilities show a reasonable agreement with previous UCCSD(T) and restricted-open-shell-MBPT(2) values.

KEYWORDS:

• Coupled-cluster theory
• coupled-cluster response treatment of properties
• massively parallel coupled-cluster implementations to evaluate properties
• static dipole polarisabilities

Acknowledgments

The authors are indebted to Mr Austin Privett (graduate student at Texas Tech University: TTU) for his assistance to prepare the figures for this manuscript. All the present calculations have been performed at the TTU High Performance Computer Center (TTU HPCC), The University of Florida High Performance Computer Center (HyperGator), the TTU Chemistry Computer Cluster (TTU CCC), and the Texas Advanced Computing Cluster (TACC) at the University of Texas at Austin. The authors thank the TTU HPCC and TACC for providing free computer time to run some of the present calculations.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The American Chemical Society Petroleum Research Fund [grant number PRF#51773-ND6].