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| Main Authors: | , , , |
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| Format: | Preprint |
| Published: |
2024
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2401.06929 |
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| _version_ | 1866929208604753920 |
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| author | Kick, Matthias Alexander, Ezra Beiersdorfer, Anton Van Voorhis, Troy |
| author_facet | Kick, Matthias Alexander, Ezra Beiersdorfer, Anton Van Voorhis, Troy |
| contents | An accurate treatment of electronic spectra in large systems with a technique such as time dependent density functional theory (TDDFT) is computationally challenging. Due to the Nyquist sampling theorem, direct real time simulations must be prohibitively long in order to recover a suitably sharp resolution in frequency space. Super-resolution techniques such as compressed sensing and MUSIC assume only a small number of excitations contribute to the spectrum, which fails in large molecular systems where the number of excitations is typically very large. We present a new approach that combines exact short time dynamics with approximate frequency space methods to capture large narrow features embedded in a dense manifold of smaller nearby peaks. We show that our approach can accurately capture narrow features and broad quasi-continuum of states at the same time - even when the features overlap in frequency. Our approach is able reduce the required simulation time by a factor of 20-40 with respect to standard Fourier analysis and shows promise for the accurate whole-spectrum prediction of large molecules and materials. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2401_06929 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Broad Yet Narrow: Super-resolution techniques to simulate electronic spectra of large molecular systems Kick, Matthias Alexander, Ezra Beiersdorfer, Anton Van Voorhis, Troy Materials Science An accurate treatment of electronic spectra in large systems with a technique such as time dependent density functional theory (TDDFT) is computationally challenging. Due to the Nyquist sampling theorem, direct real time simulations must be prohibitively long in order to recover a suitably sharp resolution in frequency space. Super-resolution techniques such as compressed sensing and MUSIC assume only a small number of excitations contribute to the spectrum, which fails in large molecular systems where the number of excitations is typically very large. We present a new approach that combines exact short time dynamics with approximate frequency space methods to capture large narrow features embedded in a dense manifold of smaller nearby peaks. We show that our approach can accurately capture narrow features and broad quasi-continuum of states at the same time - even when the features overlap in frequency. Our approach is able reduce the required simulation time by a factor of 20-40 with respect to standard Fourier analysis and shows promise for the accurate whole-spectrum prediction of large molecules and materials. |
| title | Broad Yet Narrow: Super-resolution techniques to simulate electronic spectra of large molecular systems |
| topic | Materials Science |
| url | https://arxiv.org/abs/2401.06929 |