Size extensivity of a general‐model‐space state‐universal coupled‐cluster method
Bibliographic record
Abstract
Abstract We show that the recently formulated general‐model‐space (GMS), state‐universal (SU), coupled‐cluster (CC) method, exploiting the so‐called C‐conditions, is size extensive (in the sense that the energy of a composite system consisting of noninteracting subsystems equals the sum of the subsystem energies, while employing the appropriate method in each case). This assumes that the reference or model space employed for the composite system is size consistent, i.e., is given by a tensor product of subsystem model spaces. For pedagogical reasons, the demonstration is carried out for the single reference case before the multireference SU CC case is addressed. The importance of the C‐conditions and a relationship with earlier approaches is discussed, as well as the limiting case of a complete‐model‐space SU CC method. Finally, the size extensivity of a GMS‐based SU CCSD method is illustrated by actual numerical examples. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".