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REVIEW 3 major objections 5 minor 45 references

Transcorrelated Theory for Transition Metal Atoms

T0 review · 3 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash

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Pith's one-line read Transcorrelated theory brings all ten 3d transition-metal atoms to chemical accuracy.

desk verdict Useful benchmark study of xTC-PP on Sc-Zn with honest reporting; abstract overclaims 'chemical accuracy for all atoms', and the 1-RDM-based 2-RDM in Eq. 12 needs scrutiny, but the work deserves peer review. read the letter →

arxiv 2506.10429 v1 pith:FFFYZ2EA submitted 2025-06-12 physics.chem-ph

Kristoffer Simula , Maria-Andreea Filip , Ali Alavi This is my paper · ORCID
classification physics.chem-ph
keywords transcorrelatedmethodstransitionmetalatomspseudopotentialschemicalaccuracyionizationpotentials4s-3dexcitationscoupledclusterFCIQMC
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

Transition-metal atoms are notoriously hard for quantum chemistry because the open 3d shell mixes static and dynamic correlation, relativistic effects cannot be ignored, and basis-set extrapolation is usually required for benchmark accuracy. This paper claims that a transcorrelated Hamiltonian, built with the xTC approximation and combined with scalar-relativistic pseudopotentials, removes those bottlenecks: treating the 3s and 3p semicore as valence and freezing only 1s–2p, it reproduces experimental ionization potentials and $4s\to 3d$ excitation energies for all ten atoms Sc–Zn within $\pm 1$ kcal/mol using aug-cc-pVTZ or aug-cc-pVQZ basis sets. The claim matters because it would make benchmark-quality transition-metal chemistry available in modest basis sets without complete-basis-set extrapolation or separate scalar-relativistic Hamiltonian corrections, and it points toward a practical route for transcorrelated methods on heavier transition-metal molecules and solids.

What carries the argument

The load-bearing object is the second-quantized transcorrelated Hamiltonian $\hat{H}_{\mathrm{TC}} = e^{J} \hat{H} e^{-J}$, evaluated in the xTC approximation so that only one- and two-body operators survive, with extra commutator terms accounting for the electron–nucleus pseudopotential. The Jastrow factor $J$ is optimized by variance minimization on a trial wave function from FCIQMC, and the one-body density matrix from FCIQMC is used to approximate the two-body density matrix as an antisymmetrized product (Eq. 12). This Hamiltonian moves correlation into the operator, compactifies the wave function, and suppresses basis-set error, which is why coupled cluster and FCIQMC both reach chemical accuracy in triple- or quadruple-zeta bases.

What would settle it

Compute the same Sc–Zn excitation energies and ionization potentials with an explicit two-body density matrix from FCIQMC, instead of the antisymmetrized product, and compare the results; if the differences exceed roughly 1 kcal/mol for any atom, or if a strongly correlated case such as Cr or Fe changes by that amount, the approximation is load-bearing and the claimed accuracy is not intrinsic to the transcorrelated Hamiltonian.

Watch

Extended reading notes

Core claim

The central discovery is that the transcorrelated workflow with pseudopotentials is consistently chemically accurate for transition-metal atoms in affordable basis sets. With the full semicore (3s, 3p) included in the valence and only 1s–2p frozen, xTC-FCIQMC gives $4s\to 3d$ excitation energies with a mean absolute error of 0.39 kcal/mol in aug-cc-pVQZ across Sc–Cu, and xTC-CCSDT gives ionization potentials with a mean absolute error of 0.55 kcal/mol across Sc–Zn; in most cases aug-cc-pVTZ already suffices. The paper further finds that total energies from xTC-CCSD(T), xTC-CCSDT, and xTC-FCIQMC agree to within a few millihartree even when using different orbital sets (Hartree–Fock, DFT, or state-averaged CASSCF), which it reads as evidence that the transcorrelated Hamiltonian is robust to the choice of reference orbitals and that wave-function compactification (typical $\xi \approx 0.3$) is what makes low-rank methods accurate.

Load-bearing premise

The two-body part of the transcorrelated Hamiltonian is built from the one-body density matrix through the antisymmetrized-product approximation of Eq. (12); if that reconstruction is inaccurate for strongly correlated 3d states, the Hamiltonian is biased even though the final energies agree with experiment, because both coupled cluster and FCIQMC use the same approximate Hamiltonian.

Editorial extensions

If this is right

  • Benchmark-quality ionization potentials and $4s\to 3d$ excitation energies for all ten 3d transition metals can be obtained without complete-basis-set extrapolation and without separate scalar-relativistic all-electron Hamiltonians.
  • xTC-CCSDT, used alone without FCI corrections, reaches chemical accuracy for Sc–Zn ionization potentials in aug-cc-pVQZ.
  • xTC-FCIQMC in aug-cc-pVQZ gives a $4s\to 3d$ excitation mean absolute error of 0.39 kcal/mol for Sc–Cu, matching the accuracy of previous coupled-cluster benchmark results.
  • Wave-function compactification of about $\xi \approx 0.3$ means lower excitation levels suffice with a transcorrelated Hamiltonian, making both coupled-cluster and FCIQMC calculations cheaper.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A direct test of the paper's route is to apply the same xTC-plus-pseudopotential workflow to 4d and 5d transition metals (for example Mo or W), where scalar-relativistic and core-correlation effects are stronger; the paper's logic predicts chemical accuracy in modest basis sets without complete-basis-set extrapolation.
  • Because the Jastrow factor is optimized separately per state and basis, the robustness claim may weaken in molecules where a single Jastrow cannot be optimized to the same variance; a transition-metal diatomic test would expose the limits.
  • If explicit two-body density matrices replace the antisymmetrized-product reconstruction, the agreement between xTC-CCSDT and xTC-FCIQMC might change for the most strongly correlated atoms; observing whether total-energy agreement persists would separate Hamiltonian bias from solver accuracy.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 5 minor

Summary. The paper benchmarks transcorrelated (TC) theory with pseudopotentials for the 3d transition metal atoms Sc–Zn, computing 4s→3d excitation energies and first ionization potentials. The workflow combines orbital generation (HF/DFT/SA-CASSCF), FCIQMC-based trial wavefunctions, VMC-optimized Jastrow factors, and the xTC approximation of the transcorrelated Hamiltonian, with energies obtained from xTC-CCSD(T), xTC-CCSDT, and xTC-FCIQMC. The authors report mean absolute errors of 0.39 kcal/mol for excitations (AVQZ) and 0.55 kcal/mol for ionization potentials (xTC-CCSDT, AVQZ), and claim chemical accuracy for all atoms and properties without complete-basis-set extrapolation or Douglas–Kroll–Hess Hamiltonians.

Significance. If the results hold, this is a practically valuable demonstration that transcorrelation with pseudopotentials can reach near-experimental accuracy for a notoriously difficult row of atoms with modest basis sets and without explicit relativistic corrections. The explicit comparison to external experimental benchmarks and to prior coupled-cluster results [5] is a strength. The main advertised claim—chemical accuracy for every atom and property—is not supported by the paper's own data for the ionization potentials of V and Co. In addition, the xTC Hamiltonian is constructed using a 2-RDM reconstructed from the 1-RDM (Eq. 12), an approximation whose accuracy is not assessed for the strongly correlated open-shell states; this is a load-bearing modeling assumption because both correlated solvers share the same approximate Hamiltonian.

major comments (3)
  1. [Abstract; Section 6.5; Section 7] The statement 'chemical accuracy for all atoms and properties' is contradicted by Table 3: the xTC-CCSDT AVQZ ionization potentials for V and Co are -1.42 and -1.54 kcal/mol, respectively, which are outside the ±1 kcal/mol band. The MAE of 0.55 kcal/mol reflects average accuracy, not per-system chemical accuracy. The abstract, Section 6.5, and the Conclusions should be revised to state that chemical accuracy is achieved on average (MAE < 1 kcal/mol) but with individual outliers for V and Co IPs.
  2. [Section 4.5, Eq. (12)] The xTC Hamiltonian is built from a two-body density matrix reconstructed as the antisymmetrized product of the one-body density matrix (Eq. 12), with the note that explicit 2-RDMs are 'under active investigation.' For strongly correlated open-shell 3d states, this reconstruction may introduce a systematic bias in the Hamiltonian itself. Because both xTC-CCSDT and xTC-FCIQMC solve the same approximate Hamiltonian, their mutual agreement (Fig. 3) cannot validate the Hamiltonian. The authors should provide quantitative evidence for the accuracy of Eq. 12 (e.g., by comparing against explicit 2-RDMs for a subset of atoms, or by showing that results are insensitive to the reconstruction), or discuss the potential error and its possible cancellation in energy differences.
  3. [Section 4.6, Eqs. (14)–(15)] The excited-state FCIQMC procedure orthogonalizes right eigenvectors (Eqs. 14–15), which is not formally correct for the non-Hermitian xTC Hamiltonian, as the right eigenvectors are not orthogonal. The authors justify this by citing a Hubbard model study [17], but the convergence to the correct excited-state energy for the molecular TC Hamiltonian is not guaranteed. The paper should provide additional validation for the excited-state energies, for example by comparing a few cases against a separate multireference method or against exact diagonalization in a small active space, to rule out a systematic bias in the 4s→3d excitation energies.
minor comments (5)
  1. [Abstract; Section 6.3; Section 7] There are several typographical errors in the expanded basis-set labels, such as 'A VTZ', 'A VZT', and 'A VQZ' instead of 'AVTZ' and 'AVQZ'.
  2. [Section 2] The notation 'spin quantum numbers Sz = m−2 and Sz = m' appears to use 2S_z rather than S_z (e.g., for Sc, m−2 = 1 corresponds to a doublet and m = 3 to a quartet). This should be defined explicitly to avoid confusion.
  3. [Table 3] The ionization potential entries for Ni are given to inconsistent precision (e.g., -2.196 and -0.705 for AVTZ and AVQZ), while other entries use two decimals. Uniform precision would improve readability.
  4. [Section 6.5] The statement that 'The table shows that in a quadruple-zeta basis set the xTC-FCIQMC and the xTC-CCSDT methods deliver chemical accuracy for all of the transition-metal atoms studied' is inconsistent with the V and Co IPs in the same table; this sentence should be amended for consistency.
  5. [Section 7] The conclusions repeat the 'chemical accuracy for atoms Sc–Zn' claim for IPs; this should be qualified as above, and the typo 'A VZT' should be corrected.

Circularity Check

0 steps flagged · score 1.0 of 10

No circular derivation: target IPs and excitation energies are benchmarked against external experiment, and Eq. (12) is an approximation, not a fit to the reported gaps.

full rationale

Walked the derivation chain. The final numbers in Table 3 are energy differences between separately computed total energies (or replica FCIQMC states) and are compared with experimental values from Refs. [40]–[45]; none of these experimental values enters the construction of H_TC. The Jastrow parameters are optimized by minimizing Eq. (2) (the variance of the reference energy), not by minimizing errors in IPs or excitation energies. Section 5 states that Jastrows are optimized separately per system, basis set, and PP combination, with the same Jastrow used for ground and excited states in direct excitation calculations, which removes any channel for gap-fitting. The 1-RDM entering F and V through Eq. (12) comes from a preliminary FCIQMC run (Section 4.3) and is an internal, state-dependent input; Eq. (12) is explicitly flagged as an antisymmetrized-product reconstruction, with explicit 2-RDMs described as 'under active investigation'. This is a modeling approximation whose bias would be shared by xTC-CCSDT and xTC-FCIQMC, but a shared bias is not the same as circularity: the target observables are not defined in terms of the fitted parameters, and the agreement with experiment is an independent external check. The method rests on prior work by the same authors, notably the xTC approximation (Ref. [20]), the pseudopotential extension (Ref. [21]), and the Hubbard-model excited-state demonstration (Ref. [17]); these are self-citations, but they supply algorithms and formal results rather than the TM-atom benchmark values, so they do not force the reported IPs or gaps. The abstract's blanket claim of 'chemical accuracy for all atoms and properties' is not supported by the paper's own Table 3 (for example, the V and Co xTC-CCSDT AVQZ ionization potentials are -1.42 and -1.54 kcal/mol, outside the ±1 kcal/mol band), but that is a correctness or calibration issue, not a circularity. No step in the derivation reduces to its own input.

Assumptions & free parameters 3 free parameters · 4 assumptions · 0 invented entities

The central results rest on a chain of methodological choices: a system-specific Jastrow factor, the xTC three-body neglect, 1-RDM-based 2-RDM reconstruction, and pseudopotential transferability. These are not benchmarked against an independent exact reference within the paper, so the agreement with experiment is the main evidence.

free parameters (3)
  • Jastrow parameters (alpha_u, alpha_chi, alpha_f) = per-atom, per-basis, per-PP; not listed in text
    Optimized by VMC variance minimization (Section 4.4) for each system; the final energies depend on these fitted parameters.
  • Jastrow cutoff radii = u: 4.5, chi: 1, f: 1
    Chosen by hand (Section 5); affect the flexibility of the Jastrow factor.
  • Trial wavefunction determinant count = 100
    Truncation of FCIQMC coefficients used to build the VMC trial wavefunction (Section 4.4).
assumptions (4)
  • domain assumption The xTC approximation neglects three-body interaction terms without significant loss of accuracy (Eq. 3, Ref [20]).
    The entire workflow uses the xTC Hamiltonian; no error estimate for this approximation is given for TM atoms.
  • domain assumption The antisymmetrized product of the 1-RDM (Eq. 12) is an adequate replacement for the true 2-RDM in the TC Hamiltonian.
    The paper flags explicit 2-RDMs as under investigation; all results depend on this reconstruction.
  • domain assumption eCEPP/ccECP pseudopotentials accurately capture scalar relativistic effects and semicore-valence interactions (Section 3).
    Taken from prior literature [22,23]; the paper uses them as replacement for DKH theory.
  • domain assumption The orthogonalized replica propagation (Eqs. 14-15) yields correct excited-state energies for the non-Hermitian TC Hamiltonian.
    Borrowed from Hubbard model study [17]; no rigorous proof for molecular TC Hamiltonians is provided.

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Cite this review

Pith. "Pith review of Transcorrelated Theory for Transition Metal Atoms." pith.science (2026). https://pith.science/paper/FFFYZ2EA

@misc{pith2026250610429,
  author       = {Pith},
  title        = {Pith review of: Transcorrelated Theory for Transition Metal Atoms},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/FFFYZ2EA}},
  note         = {Machine review of arXiv:2506.10429}
}
read the original abstract

We benchmark ionisation and excitation energies of transition-metal atoms Sc-Zn with a transcorrelated Hamiltonian combined with pseudopotentials. The similarity transformed Hamiltonian provides compact TC wave functions in affordable aug-cc-pVTZ and aug-cc-pVQZ Gaussian bases and eliminates the need for complete basis set extrapolations. The use of Douglas-Kroll-Hess theory is omitted because scalar relativistic effects are included in the pseudopotentials. Treating the full semicore (3s 3p) valence and freezing only 1s-2p shells, we reach chemical accuracy for all atoms and properties with coupled cluster and full configuration interaction quantum Monte Carlo. Consistent total energies across disparate orbital sets and correlation solvers highlights the robustness of the TC workflow. Our study pushes benchmark-quality quantum chemistry into the 3d block without large-scale basis sets and opens a practical route for transcorrelation to strongly correlated molecules and materials hosting heavier transition metals.

Figures

Figures reproduced from arXiv: 2506.10429 by the authors.

Figure 1
Figure 1. Computational workflow for transcorrelated theory applied to transition metals. The [PITH_FULL_IMAGE:figures/full_fig_p004_1.png] view at source ↗
Figure 2
Figure 2. Energies of orbitals 4s and 3d, obtained with SA-CASSCF (4s black and 3d grey) and [PITH_FULL_IMAGE:figures/full_fig_p010_2.png] view at source ↗
Figure 3
Figure 3. Total energies of the transition metals Sc–Zn, calculated with xTC-CCSD(T) (squares), [PITH_FULL_IMAGE:figures/full_fig_p012_3.png] view at source ↗
Figures from the paper (2 more)
Figure 4
Figure 4. Figure 4: Errors in 4s → 3d electronic excitation energies of atoms Sc–Cu, evaluated with xTC￾FCIQMC against experimental values, ∆E = ETheory − EExpt. . Multiple basis sets (AVDZ, AVTZ, AVQZ) are shown. For each element and basis set, we plot a number of results with varying wa…
Figure 5
Figure 5. Figure 5: Errors in theoretical ionization potentials against experimental values for the transition [PITH_FULL_IMAGE:figures/full_fig_p014_5.png]

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Reference graph

Works this paper leans on

45 extracted references · 44 canonical work pages

  1. [5]

    Balabanov and Kirk A

    Nikolai B. Balabanov and Kirk A. Peterson. Basis set limit electronic excitation energies, ionization potentials, and electron affinities for the 3d transition metal atoms: Coupled cluster and multireference methods.The Journal of Chemical Physics, 125(7):074110, 08 2006

    work page 2006

  2. [17]

    Compact numerical solutions to the two- dimensional repulsive hubbard model obtained via nonunitary similarity transformations.Phys

    Werner Dobrautz, Hongjun Luo, and Ali Alavi. Compact numerical solutions to the two- dimensional repulsive hubbard model obtained via nonunitary similarity transformations.Phys. Rev. B, 99:075119, 2019. 18

    work page 2019

  3. [1]

    Phase- less auxiliary-field quantum monte carlo on graphical processing units.Journal of chemical theory and computation, 14(8):4109–4121, 2018

    James Shee, Evan J Arthur, Shiwei Zhang, David R Reichman, and Richard A Friesner. Phase- less auxiliary-field quantum monte carlo on graphical processing units.Journal of chemical theory and computation, 14(8):4109–4121, 2018

    work page 2018

  4. [2]

    James Shee, Benjamin Rudshteyn, Evan J Arthur, Shiwei Zhang, David R Reichman, and Richard A Friesner. On achieving high accuracy in quantum chemical calculations of 3 d transition metal-containing systems: a comparison of auxiliary-field quantum monte carlo with coupled cluster, density functional theory, and experiment for diatomic molecules.Journal of ...

    work page 2019

  5. [3]

    Hagen Neugebauer, Hung T Vuong, John L Weber, Richard A Friesner, James Shee, and Andreas Hansen. Toward benchmark-quality ab initio predictions for 3d transition metal electrocatalysts: A comparison of ccsd (t) and ph-afqmc.Journal of Chemical Theory and Computation, 19(18):6208–6225, 2023. 17

    work page 2023

  6. [4]

    Thomas, George H

    Robert E. Thomas, George H. Booth, and Ali Alavi. Accurate ab initio calculation of ionization potentials of the first-row transition metals with the configuration-interaction quantum monte carlo technique.Phys. Rev. Lett., 114:033001, Jan 2015

    work page 2015

  7. [6]

    An arbitrary order douglas-kroll method with polynomial cost.The Journal of Chemical Physics, 130(4):044102, 01 2009

    Daoling Peng and Kimihiko Hirao. An arbitrary order douglas-kroll method with polynomial cost.The Journal of Chemical Physics, 130(4):044102, 01 2009

    work page 2009

  8. [7]

    Balabanov and Kirk A

    Nikolai B. Balabanov and Kirk A. Peterson. Systematically convergent basis sets for transition metals. i. all-electron correlation consistent basis sets for the 3d elements sc–zn.The Journal of Chemical Physics, 123(6):064107, 08 2005

    work page 2005

Show all 45 references
  1. [8]

    Hongjun Luo and Ali Alavi. Combining the transcorrelated method with full configuration interaction quantum monte carlo: Application to the homogeneous electron gas.Journal of Chemical Theory and Computation, 14(3):1403–1411, 2018

    2018

  2. [9]

    Similarity transformation of the electronic schr¨ odinger equation via jastrow factorization.The Journal of Chemical Physics, 151(6), 2019

    Aron J Cohen, Hongjun Luo, Kai Guther, Werner Dobrautz, David P Tew, and Ali Alavi. Similarity transformation of the electronic schr¨ odinger equation via jastrow factorization.The Journal of Chemical Physics, 151(6), 2019

    2019

  3. [10]

    Transcorrelated selected config- uration interaction in a bi-orthonormal basis and with a cheap three-body correlation factor

    Abdallah Ammar, Anthony Scemama, and Emmanuel Giner. Transcorrelated selected config- uration interaction in a bi-orthonormal basis and with a cheap three-body correlation factor. The Journal of Chemical Physics, 159(11), 2023

    2023

  4. [11]

    Abdallah Ammar, Anthony Scemama, and Emmanuel Giner. Biorthonormal orbital optimiza- tion with a cheap core-electron-free three-body correlation factor for quantum monte carlo and transcorrelation.Journal of Chemical Theory and Computation, 19(15):4883–4896, 2023

    2023

  5. [12]

    Studies on the transcorrelated method.Journal of Chemical Theory and Computation, 19(17):5743–5759, 2023

    Nicholas Lee and Alex JW Thom. Studies on the transcorrelated method.Journal of Chemical Theory and Computation, 19(17):5743–5759, 2023

    2023

  6. [13]

    Nonunitary projective transcorrelation theory inspired by the f12 ansatz

    Seiichiro L Ten-No. Nonunitary projective transcorrelation theory inspired by the f12 ansatz. The Journal of Chemical Physics, 159(17), 2023

    2023

  7. [14]

    Compact- ification of determinant expansions via transcorrelation.The Journal of Chemical Physics, 161(8):084104, 08 2024

    Abdallah Ammar, Anthony Scemama, Pierre-Fran¸ cois Loos, and Emmanuel Giner. Compact- ification of determinant expansions via transcorrelation.The Journal of Chemical Physics, 161(8):084104, 08 2024

    2024

  8. [15]

    Optimizing jastrow factors for the transcorrelated method.The Journal of Chemical Physics, 158(22), 2023

    J Philip Haupt, Seyed Mohammadreza Hosseini, Pablo L´ opez R ´ ıos, Werner Dobrautz, Aron Cohen, and Ali Alavi. Optimizing jastrow factors for the transcorrelated method.The Journal of Chemical Physics, 158(22), 2023

    2023

  9. [16]

    Philip Haupt, Evelin Martine Corvid Christlmaier, Daniel Kats, and Ali Alavi

    Maria-Andreea Filip, Pablo L´ opez R ´ ıos, J. Philip Haupt, Evelin Martine Corvid Christlmaier, Daniel Kats, and Ali Alavi. Transcorrelated methods applied to second row elements.The Journal of Chemical Physics, 162(6):064110, 02 2025

    2025

  10. [18]

    Cohen, Ali Alavi, and Daniel Kats

    Thomas Schraivogel, Aron J. Cohen, Ali Alavi, and Daniel Kats. Transcorrelated coupled cluster methods.The Journal of Chemical Physics, 155(19):191101, 2021

    2021

  11. [19]

    Transcorrelated coupled cluster methods

    Thomas Schraivogel, Evelin Martine Corvid Christlmaier, Pablo L´ opez R ´ ıos, Ali Alavi, and Daniel Kats. Transcorrelated coupled cluster methods. ii. molecular systems.The Journal of Chemical Physics, 158(21):214106, 2023

    2023

  12. [20]

    xtc: An efficient treatment of three-body interactions in transcorrelated methods

    Evelin Martine Corvid Christlmaier, Thomas Schraivogel, Pablo L´ opez R ´ ıos, Ali Alavi, and Daniel Kats. xtc: An efficient treatment of three-body interactions in transcorrelated methods. The Journal of Chemical Physics, 159(1), 2023

    2023

  13. [21]

    Philip Haupt, Daniel Kats, Pablo Lopez-Rios, and Ali Alavi

    Kristoffer Simula, Evelin Martine Corvid Christlmaier, Maria-Andreea Filip, J. Philip Haupt, Daniel Kats, Pablo Lopez-Rios, and Ali Alavi. Transcorrelated theory with pseudopotentials. Journal of Chemical Theory and Computation, 0(0):null, 0

  14. [22]

    J. R. Trail and R. J. Needs. Shape and energy consistent pseudopotentials for correlated electron systems.The Journal of Chemical Physics, 146(20):204107, 05 2017

    2017

  15. [23]

    Melton, M

    Abdulgani Annaberdiyev, Guangming Wang, Cody A. Melton, M. Chandler Bennett, Luke Shulenburger, and Lubos Mitas. A new generation of effective core potentials from correlated calculations: 3d transition metal series.The Journal of Chemical Physics, 149(13):134108, 10 2018

    2018

  16. [24]

    M. Dolg, U. Wedig, H. Stoll, and H. Preuss. Energy-adjusted ab initio pseudopotentials for the first row transition elements.The Journal of Chemical Physics, 86(2):866–872, 01 1987

    1987

  17. [25]

    Quantum monte carlo methods in chemistry.New Methods in Computational Quantum Mechanics//Advances in Chemical Physics, XCIII, eds

    David M Ceperley and Lubos Mitas. Quantum monte carlo methods in chemistry.New Methods in Computational Quantum Mechanics//Advances in Chemical Physics, XCIII, eds. Prigogine I. and Rice SA,(John Willcy & Sons, Inc., NY 1996), pages 1–38, 1995

    1996

  18. [26]

    Perdew, Kieron Burke, and Matthias Ernzerhof

    John P. Perdew, Kieron Burke, and Matthias Ernzerhof. Generalized gradient approximation made simple.Phys. Rev. Lett., 77:3865–3868, Oct 1996

    1996

  19. [27]

    Axel D. Becke. Density-functional thermochemistry. iii. the role of exact exchange.The Journal of Chemical Physics, 98(7):5648–5652, 04 1993

    1993

  20. [28]

    Booth, Alex J

    George H. Booth, Alex J. W. Thom, and Ali Alavi. Fermion monte carlo without fixed nodes: A game of life, death, and annihilation in slater determinant space.The Journal of Chemical Physics, 131(5):054106, 08 2009

    2009

  21. [29]

    Exploiting locality in full configuration interaction quantum monte carlo for fast excitation generation.Journal of Chemical Theory and Computation, 19(24):9118–9135, 2023

    Oskar Weser, Ali Alavi, and Giovanni Li Manni. Exploiting locality in full configuration interaction quantum monte carlo for fast excitation generation.Journal of Chemical Theory and Computation, 19(24):9118–9135, 2023. PMID: 38051202

    2023

  22. [30]

    Booth, N

    Catherine Overy, George H. Booth, N. S. Blunt, James J. Shepherd, Deidre Cleland, and Ali Alavi. Unbiased reduced density matrices and electronic properties from full configuration interaction quantum monte carlo.The Journal of Chemical Physics, 141(24):244117, 12 2014

    2014

  23. [31]

    Transcorrelated methods for multireference problems.arXiv preprint arXiv:2505.20187, 2025

    J Philip Haupt, Evelin Christlmaier, Pablo L´ opez R ´ ıos, Nikolay A Bogdanov, Daniel Kats, and Ali Alavi. Transcorrelated methods for multireference problems.arXiv preprint arXiv:2505.20187, 2025. 19

    2025 arXiv

  24. [32]

    N. D. Drummond, M. D. Towler, and R. J. Needs. Jastrow correlation factor for atoms, molecules, and solids.Phys. Rev. B, 70:235119, 2004

    2004

  25. [33]

    Orbital optimisation in xtc transcorrelated methods.Faraday Discussions, 2024

    Daniel Kats, Evelin MC Christlmaier, Thomas Schraivogel, and Ali Alavi. Orbital optimisation in xtc transcorrelated methods.Faraday Discussions, 2024

    2024

  26. [34]

    N. S. Blunt, Simon D. Smart, George H. Booth, and Ali Alavi. An excited-state approach within full configuration interaction quantum monte carlo.The Journal of Chemical Physics, 143(13):134117, 10 2015

    2015

  27. [35]

    Recent developments in the pyscf program package.The Journal of chemical physics, 153(2), 2020

    Qiming Sun, Xing Zhang, Samragni Banerjee, Peng Bao, Marc Barbry, Nick S Blunt, Nikolay A Bogdanov, George H Booth, Jia Chen, Zhi-Hao Cui, et al. Recent developments in the pyscf program package.The Journal of chemical physics, 153(2), 2020

    2020

  28. [36]

    Variational and diffusion quantum monte carlo calculations with the casino code.The Journal of chemical physics, 152(15):154106, 2020

    RJ Needs, MD Towler, ND Drummond, P L´ opez R ´ ıos, and JR Trail. Variational and diffusion quantum monte carlo calculations with the casino code.The Journal of chemical physics, 152(15):154106, 2020

    2020

  29. [37]

    Daniel Kats, Thomas Schraivogel, Johannes Hauskrecht, Charlotte Rickert, and Fangcheng Wu.ElemCo.jl: Julia program package for electron correlation methods.2024

    2024

  30. [38]

    Neci: N-electron configuration interaction with an emphasis on state-of-the-art stochastic methods

    Kai Guther, Robert J Anderson, Nick S Blunt, Nikolay A Bogdanov, Deidre Cleland, Nike Dat- tani, Werner Dobrautz, Khaldoon Ghanem, Peter Jeszenszki, Niklas Liebermann, et al. Neci: N-electron configuration interaction with an emphasis on state-of-the-art stochastic methods. Th...

    2020

  31. [39]

    A new generation of effective core potentials for correlated calculations.The Journal of chemical physics, 147(22), 2017

    M Chandler Bennett, Cody A Melton, Abdulgani Annaberdiyev, Guangming Wang, Luke Shulenburger, and Lubos Mitas. A new generation of effective core potentials for correlated calculations.The Journal of chemical physics, 147(22), 2017

    2017

  32. [40]

    N IV, NV, N VI, N VII, volume 4

    Charlotte Emma Moore.Selected Tables of Atomic Spectra: A, Atomic Energy Levels-B, Multiplet Tables. N IV, NV, N VI, N VII, volume 4. US National Bureau of Standards, 1971

    1971

  33. [41]

    Atomic energy levels of the iron-period elements: potassium through nickel

    Jack Sugar and Charles Corliss. Atomic energy levels of the iron-period elements: potassium through nickel. Technical report, American Chemical Society, Washington, DC, 1985

    1985

  34. [42]

    Page and Christopher S

    Ralph H. Page and Christopher S. Gudeman. Completing the iron period: double-resonance, fluorescence-dip rydberg spectroscopy and ionization potentials of titanium, vanadium, iron, cobalt, and nickel.J. Opt. Soc. Am. B, 7(9):1761–1771, Sep 1990

    1990

  35. [43]

    J. E. Sohl, Yang Zhu, and R. D. Knight. Two-color laser photoionization spectroscopy of ti i: multichannel quantum defect theory analysis and a new ionization potential.J. Opt. Soc. Am. B, 7(1):9–14, Jan 1990

    1990

  36. [44]

    James, Pawel Kowalczyk, Etienne Langlois, Margot D

    Andrew M. James, Pawel Kowalczyk, Etienne Langlois, Margot D. Campbell, Ayano Ogawa, and Benoit Simard. Resonant two photon ionization spectroscopy of the molecules v2, vnb, and nb2.The Journal of Chemical Physics, 101(6):4485–4495, 09 1994

    1994

  37. [45]

    Nist atomic spectra database (ver- sion 5.1), 2013

    Alexander Kramida, Yuri Ralchenko, JNAT Reader, et al. Nist atomic spectra database (ver- sion 5.1), 2013. 20

    2013

Pith tools

Reviewed August 7, 2026 · model on record in the stance chip above.