Beyond TD-DFT: Assessing the Bethe-Salpeter Equation within the GW Approximation for Absorption Properties
Bibliographic record
Abstract
Time-dependent density functional theory (TD-DFT) has been the “go-to” source for predicting optical absorption properties, balancing computational efficiency and reasonable accuracy. However, the Bethe–Salpeter equation within the GW approximation (GW/BSE) is rapidly emerging as a powerful alternative to overcoming key limitations of TD-DFT. This letter presents a comprehensive evaluation of one-photon and two-photon absorption (1PA and 2PA) properties across a chemically diverse set of fluorophores, evaluating TD-DFT and GW/BSE relative to resolution-of-identity second-order approximate coupled-cluster (RI-CC2). While TD-DFT maintains its dominance for 1PA, GW/BSE exhibits superiority in 2PA, offering lower absolute errors and stronger agreement with qualitative trends. A persistent challenge in TD-DFT is the trade-off between quantitative accuracy and capturing structure–property trends, with no single functional reliably achieving both. In contrast, GW/BSE overcomes this limitation, offering reliable values alongside robust linear correlation. These findings establish GW/BSE as a promising framework for modeling optical properties beyond TD-DFT.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".