{"id":"eeef9dd6-473a-465e-a6b5-6c163fad9ae6","arxiv_id":"2607.19551","paper_version":1,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":7.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":1,"one_line_summary":"A parameter-free ab initio framework constructs semi-infinite crystal–vacuum scattering states from Wannier Hamiltonians plus Green-function embedding, and predicts Ag(111) quantum efficiency and mean transverse energy on the experimental scale.","lead":"This paper builds open-boundary 'scattering states' for electrons escaping a crystal into vacuum, and uses them to predict how much current Ag(111) emits when illuminated near threshold. It matters because photoemission simulations usually box the electron in, while these states respect the true semi-infinite crystal–vacuum geometry and still hit the experimental scale.","discovery_kind":"new_method","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Untested finite-slab truncation of occupied states is the key weak point: absolute QE/MTE scale depends on it, and no convergence data is reported.","rationale":"The reader's weakest_assumption identifies exactly the load-bearing gap: the occupied initial states come from a finite-slab diagonalization with no convergence evidence. This is the single most important unresolved assumption because the paper's headline claims of absolute QE and MTE depend on the surface-state energy and occupation, and the paper itself acknowledges that the remaining discrepancies are tied to the surface/bulk balance. The final-state continuum normalization is indirectly tested by the absolute QE scale—if it were globally wrong, the scale would fail everywhere—whereas the occupied-state truncation can alter the energy dependence and angular dependence without a uniform scale error. The End Matter assertion that the states 'were converged' is precisely the kind of missing support that a referee should request. The proposed convergence test is concrete and would settle the concern: if the observables are stable against doubling the number of appended layers, the finite truncation is benign; if not, the quantitative claims require revision. The reader's CONDITIONAL verdict is appropriate; the test would firm it up without changing the verdict unless the convergence test fails.","tokens_in":9642,"tokens_out":13632,"duration_ms":139150,"concrete_test":"Recompute the occupied spectrum and the observables in Figs. 3–5 for N = 10, 20, 40, and 80 appended bulk principal layers, using at least two distinct far-end boundary conditions (e.g., hard wall and bulk-periodic continuation). For each N, report the Shockley surface-state energy relative to the Fermi level, the absolute QE at ℏω−ϕ = 0.12 eV, and the MTE at ℏω−ϕ = 0.05, 0.12, and 0.25 eV. If doubling N from 40 to 80 changes QE or MTE by more than ~10%, the finite-slab truncation is not converged and the claimed absolute scale is not yet established; if changes are below ~5%, the concern is resolved.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The paper's central claim is that the same ab initio construction yields absolute photoemission observables on the experimental scale. Near threshold, the QE and MTE are dominated by the Shockley surface state and the surface/bulk emission balance. The occupied initial states, however, are not obtained from the semi-infinite scattering construction but by 'diagonalizing a large finite Hamiltonian' with 'many bulk principal layers' appended (End Matter, Occupied-state construction). This introduces an artificial termination whose distance is never specified and whose convergence is asserted without data. If the termination shifts the surface-state energy relative to the Fermi level, or if the discrete occupied bulk states do not yet sample the near-surface continuum densely enough, the threshold onset in Fig. 3 and the surface/bulk balance in Figs. 4 and 5 would change. The paper explicitly attributes the remaining shape discrepancies to 'the relative weight of surface-state and bulk-state emission', so the occupied-state construction is load-bearing. The statement that states 'were converged with respect to the artificial termination' is an unsupported claim; no layer counts, no energy shifts, and no observable convergence tests are given.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper presents an ab initio one-step photoemission formalism for semi-infinite crystal–vacuum interfaces. It combines hybrid Wannier functions, Green-function embedding of semi-infinite leads, and first-principles G0W0/Fan–Migdal self-energies to construct time-reversed LEED final states with microscopically computed attenuation. For Ag(111), the method is used to predict absolute quantum efficiency, the vectorial photoelectric effect, and mean transverse energy; the results are compared directly with experiment on an absolute scale without rescaling. The central claim is that this procedure is parameter-free and removes the need for a periodic box, an empirical optical potential, or an externally imposed inelastic mean free path.","tokens_in":9912,"tokens_out":3858,"duration_ms":42207,"significance":"If the construction is sound, this is a significant advance for first-principles photoemission: it supplies explicit open-boundary scattering wave functions rather than transmission probabilities, and it replaces phenomenological damping with computed self-energies. The absolute-scale agreement for Ag(111) QE and MTE is a nontrivial, falsifiable test that goes beyond the usual band-structure comparisons. The method's applicability to other interfaces is also plausible. However, the validation depends on two under-documented elements — the finite-slab construction of the occupied initial states and the inputs entering the Fresnel optical field — so the significance is currently conditional.","major_comments":[{"comment":"The occupied initial states, which dominate the near-threshold emission and the surface/bulk balance, are obtained by diagonalizing a finite Hamiltonian with 'many bulk principal layers appended,' but no layer count, no energy-shift data, and no observable convergence tests are reported. The claim that the states 'were converged with respect to the artificial termination' is therefore unsupported. This is load-bearing: the paper itself attributes the remaining QE shape discrepancies to 'the relative weight of surface-state and bulk-state emission' (Results, QE paragraph). Please provide convergence of the Shockley surface-state energy and occupation, and of the computed QE and MTE, as a function of the number of appended bulk layers. Also specify how the finite set of occupied bulk states samples the near-surface continuum and whether the thresholds in Fig. 3 shift with termination.","section":"End Matter, Occupied-state construction"},{"comment":"The abstract and conclusion call the approach 'parameter-free,' but the optical field entering Eq. (19) is determined by the complex dielectric function of Ag, described as the sum of an independent-particle interband response and a metallic intraband Drude response 'following Ref. [19].' It is not stated whether the Drude plasma frequency, damping rate, or any other dielectric input is computed from first principles or taken from experiment/fitted. Since the absolute QE and the vectorial effect depend sensitively on the Fresnel-transmitted field and on the delta-function surface term, any empirical or fitted dielectric parameter would directly affect the headline claim. Please list all parameters entering ε and state explicitly whether any is adjusted to improve agreement with the photoemission data.","section":"Methods, Optical Transition Matrix Elements and Eq. (19)"},{"comment":"The vacuum sector is an essential part of the open-boundary construction, but the regular close-packed vacuum Wannier lattice is said to be 'developed in Ref. [14],' which appears to be an unpublished companion paper. The brief description in the End Matter (Gaussian trial orbitals projected onto the empty-state manifold) is not sufficient for a reader to reproduce or independently assess the method. Please either expand the description so that the vacuum Wannier construction is self-contained, or provide a published or otherwise available reference with full computational details.","section":"End Matter, Hybrid Wannier construction"}],"minor_comments":[{"comment":"The title contains a typo: 'AnAb Initio' should be 'An Ab Initio.'","section":"Title"},{"comment":"The y-axis label 'Absolute QE 1e 5' is ambiguous; it appears to indicate a multiplicative factor of 10^5, but the figure would be clearer with explicit units (e.g., 'QE (×10^−5)').","section":"Fig. 4"},{"comment":"The word 'parameter-free' is used prominently, but the manuscript does not provide a complete list of numerical inputs (plane-wave cutoff, k-mesh densities, number of principal layers, Gaussian trial orbital widths, etc.). A concise input table or statement of defaults would make the claim verifiable.","section":"Abstract/Conclusion"},{"comment":"The text lists several sources of remaining discrepancy but does not quantify them (e.g., how much the calculated QE rises earlier at low excess energy, or the magnitude of the underestimate at higher excess energy). Quantitative error measures would strengthen the comparison and make future improvements trackable.","section":"Results, QE paragraph"},{"comment":"The surface delta-function term assumes a sharp interface at z=0 with a discontinuous dielectric function. For a real Ag(111) surface the profile has finite width; please comment on the sensitivity of the vectorial effect to this idealization and, if possible, test a broadened profile.","section":"End Matter, Optical matrix elements, Eq. (19)"}],"recommendation":"major_revision","confidential_remarks":"The central scattering-state construction is plausible and the absolute-scale comparisons are impressive, but the missing convergence data for the occupied-state finite slab is a genuine load-bearing gap. The dielectric-function input also needs full disclosure before the 'parameter-free' claim can be accepted. I would advise requesting these additions rather than rejecting; the paper is likely to be publishable after the authors provide the requested technical details and convergence tests."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Dear colleague, here's my read on arXiv:2607.19551.\n\nThe paper does something real: it constructs continuum-normalized, semi-infinite scattering states for a crystal-vacuum interface from Wannier Hamiltonians and Green-function embedding, with attenuation coming from first-principles self-energies rather than an empirical optical potential. That's a genuinely new combination, and the Ag(111) results are the right test case. The absolute QE, vectorial effect, and MTE all land on the experimental scale without any fitting parameter, which is a nontrivial benchmark that should be taken seriously.\n\nWhat the paper does particularly well is the transparent construction: the hybrid Wannier basis, the lead self-energies, the time-reversed LEED final states, and the Fresnel surface term are all laid out clearly. The inclusion of the ∇·A surface contribution is a nice piece of formalism. And the self-energies are computed from the same electronic structure, not fit to the QE, so the comparison is honest.\n\nThe soft spots are real but not fatal. The biggest is the occupied-state construction. The initial states come from diagonalizing a finite slab, not from the semi-infinite embedding, and the paper asserts convergence with respect to the artificial termination without reporting layer counts or energy shifts. The near-threshold QE and MTE are sensitive to the Shockley surface-state position and to the surface/bulk balance, so this is exactly where a referee needs the convergence data. The self-admitted shape discrepancies in all three observables also suggest that the quantitative claim is not yet as tight as the absolute scale would suggest. I would also want some sensitivity analysis — for example, how the results change with the self-energy approximation or the choice of vacuum Wannier spacing.\n\nThe reader's stress-test note is on target. It is the right criticism to raise, and the paper currently answers it with a one-sentence assertion.\n\nOverall: this is a serious methodological advance with a strong benchmark. The central construction is plausible and the open-boundary scattering states are a new object. The missing convergence tests and sensitivity analysis are the kind of support a referee should require, not reasons to reject. I'd send it to peer review.\n\nFor a reading group, yes — it's a good paper to discuss for anyone working on photoemission or embedding methods. I'd cite it if I were writing in this area.","headline":"A real advance: parameter-free semi-infinite scattering states with absolute-scale Ag(111) agreement; the occupied-state truncation needs convergence data before the quantitative claim fully lands.","tokens_in":10393,"tokens_out":2059,"would_cite":true,"duration_ms":19187,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"A parameter-free Wannier + Green-function embedding constructs continuum-normalized time-reversed LEED final states for semi-infinite crystal-vacuum interfaces, and the resulting Ag(111) photoemission observables land on the experimental sc","keywords":["photoemission","semi-infinite crystal","time-reversed LEED","Wannier functions","Green-function embedding","quantum efficiency","mean transverse energy","Ag(111)"],"falsifier":"Repeat the Ag(111) calculation with two, four, and eight additional bulk principal layers in the occupied-state construction and recompute the absolute quantum efficiency and mean transverse energy at a fixed excess photon energy; if the results shift by more than the experimental scatter, the open-boundary final states are not the sole determinant of the reported observables.","tokens_in":9504,"feed_emoji":"⚛️","tokens_out":8341,"duration_ms":62358,"temperature":0.7,"pith_summary":"Photoemission is an escape problem, but standard first-principles calculations enclose the electron in a periodic box. This paper removes that artificial boundary by building scattering states for a semi-infinite crystal-vacuum interface directly from Wannier Hamiltonians and Green-function embedding. For each transverse momentum, the problem becomes a one-dimensional open-boundary scattering problem whose solution is a continuum-normalized time-reversed LEED final state with microscopic quasiparticle attenuation. Applied to Ag(111), the method predicts absolute quantum efficiency, the vectorial photoelectric effect, and mean transverse energy on the experimental scale, without rescaling or empirical damping. This matters because it offers a route to fully ab initio one-step photoemission and other open-boundary observables for realistic materials.","feed_headline":"Semi-infinite scattering states predict absolute photoemission yield","feed_subtitle":"Ag(111) quantum efficiency, vectorial effect, MTE all land on experimental scale, no fitted parameters.","key_machinery":"The load-bearing mechanism is the hybrid Wannier representation combined with Green-function embedding. Fourier transforming maximally localized Wannier functions over lattice vectors parallel to the surface gives a short-ranged effective one-dimensional chain along the surface normal for each transverse momentum. The semi-infinite crystal and vacuum half-spaces are integrated out via retarded surface Green's functions, leaving a finite interface problem; solving it with a source term that fixes the incoming Bloch mode yields the complete scattering wave function — the continuum-normalized time-reversed LEED final state. Continuum normalization and microscopic attenuation are built in by the","core_discovery":"The central claim is that a parameter-free hybrid-Wannier plus Green-function embedding construction yields the full scattering wave function of the semi-infinite crystal-vacuum system, not merely transmission probabilities. The final states are continuum-normalized time-reversed LEED states; adding a first-principles complex self-energy to the Wannier Hamiltonian produces inelastic attenuation inside the crystal while leaving the vacuum channel propagating. Using these states in one-step photoemission matrix elements, with the Fresnel-transmitted optical field and its surface divergence included, the method reproduces the absolute scale of Ag(111) quantum efficiency, the vectorial photoelec","pith_inferences":["A natural test is to compare the energy-dependent inelastic mean free path extracted from these scattering states against independent attenuation-length measurements; the paper treats it as an output rather than an input.","The finite-slab treatment of occupied states is the least protected part of the calculation; systematic convergence checks against the number of appended bulk layers would sharpen every absolute number reported.","The interface optical field is modeled with a delta-function sheet charge; probing s- versus p-polarized emission over a broader frequency range would test that approximation independently of the electronic-structure machinery.","Because explicit wave functions are produced, the same embedding could be used for higher-order processes (for example, phonon-assisted or two-step emission) without changing the boundary-condition construction."],"forward_implications":["One-step photoemission calculations can proceed without a periodic supercell, an empirical optical potential, or a fitted inelastic mean free path.","Momentum-resolved observables and matrix elements that depend on the full quantum state become directly accessible, not just total transmission probabilities.","The same scattering-state construction applies to any lattice-matched or commensurate interface for which a localized Wannier representation exists, covering transport and interface spectroscopy.","The inelastic mean free path emerges from the first-principles self-energy, so it can be extracted as a function of energy, momentum, and temperature rather than supplied as an input.","The symmetrized optical perturbation, including the surface divergence term, gives a first-principles account of polarization-dependent emission such as the vectorial photoelectric effect."],"fun_headline_variants":["Scattering states escape the box in photoemission","Open-boundary ab initio photoemission for crystals","True photoemission final states: no more periodic box","Parameter-free photoemission from semi-infinite Ag(111)","Exact scattering states reproduce absolute photoemission yield"],"cache_read_input_tokens":2304,"weakest_assumption_plain":"The occupied initial states are obtained by diagonalizing a finite Hamiltonian with an artificial termination, and the paper gives no convergence test against the number of appended bulk layers; if that termination shifts surface-state energies or occupations relative to the Fermi level, the absolute emission yield and the surface/bulk balance would change.","fun_headline_variants_meta":{"raw":{"variants":["Scattering states escape the box in photoemission","Open-boundary ab initio photoemission for crystals","True photoemission final states: no more periodic box","Parameter-free photoemission from semi-infinite Ag(111)","Exact scattering states reproduce absolute photoemission yield"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000234,"raw_usage":{"total_tokens":1267,"prompt_tokens":609,"completion_tokens":658,"prompt_tokens_details":{"cached_tokens":256},"prompt_cache_hit_tokens":256,"prompt_cache_miss_tokens":353,"completion_tokens_details":{"reasoning_tokens":578}},"tokens_in":353,"tokens_out":658,"duration_ms":6391,"temperature":1.0,"reasoning_tokens":578,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-01T12:22:47.429160+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Repeat the Ag(111) calculation with two, four, and eight additional bulk principal layers in the occupied-state construction and recompute the absolute quantum efficiency and mean transverse energy at a fixed excess photon energy; if the results shift by more than the experimental scatter, the open-boundary final states are not the sole determinant of the reported observables.","supporting_citations":[],"review_version":1}