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arXiv · 2404.05869

Spin-free exact two-component linear response coupled cluster theory for estimation of frequency-dependent second-order property

Sudipta Chakraborty·Tamoghna Mukhopadhyay·Achintya Kumar Dutta
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Abstract

We have presented the theory, implementation, and benchmark results for the one-electronic variant of spin-free exact two-component (SFX2C1e) linear response coupled cluster (LRCCSD) theory for static and dynamic polarizabilities of atoms and molecules in the spin-adapted formulation. The resolution of identity (RI) approximation for two-electron integrals has been used to reduce the computational cost of the calculation and has been shown to have a negligible effect on accuracy. The calculated static and dynamic polarizability values agree very well with the more expensive X2C-LRCCSD and experimental results. Our calculated results show that accurate predictions of polarizabilities of atoms and molecules containing heavy atoms require the use of a large basis set containing an adequate number of diffuse functions, in addition to accounting for electron correlation and relativistic effects.

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Sudipta Chakraborty, Tamoghna Mukhopadhyay, Achintya Kumar Dutta. 2024-04-08. Spin-free exact two-component linear response coupled cluster theory for estimation of frequency-dependent second-order property. https://arxiv.org/abs/2404.05869

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