We present an approach for generating local numerical basis sets of improving accuracy for first-principles nanoplasmonics simulations within time-dependent density functional theory. The method is demonstrated for copper, silver, and gold nanoparticles that are of experimental interest but computationally demanding due to the semi-core d-electrons that affect their plasmonic response. The basis sets are constructed by augmenting numerical atomic orbital basis sets by truncated Gaussian-type orbitals generated by the completeness-optimization scheme, which is applied to the photoabsorption spectra of homoatomic metal atom dimers. We obtain basis sets of improving accuracy up to the complete basis set limit and demonstrate that the performance of the basis sets transfers to simulations of larger nanoparticles and nanoalloys as well as to calculations with various exchange-correlation functionals. This work promotes the use of the local basis set approach of controllable accuracy in first-principles nanoplasmonics simulations and beyond.
REFERENCES
This NGTO construction scheme is readily available in GPAW.
These conditions are equivalent to restricting Gaussian exponents to following limits: s-shell: 0.0090–0.93, p-shell: 0.014–1.4, d-shell: 0.019–1.9, f-shell: 0.024–2.4.
Timings were performed on Intel Xeon E5-2680 v2 processors with FDR InfiniBand interconnect.
The exact speed-up factors are likely to be affected by the choice between the different parallelization schemes.