Lucas Lang

Thanks! I did not think much about actinides, but I think that the answer is, in principle, yes.

The theory in the article requires that you parametrize all operators in terms of angular momentum / spin operators. J-mixing in actinide complexes might complicate things.

Some highlights:

• analytical third-order expression (one order beyond Bleaney's theory).
• for transition-metal and lanthanide complexes.
• based on the angular momentum / spin dyadic → different properties including NMR chemical shifts beyond the point-dipole approximation.

(2/2)

New preprint "Generalization of Bleaney's Theory": doi.org/10.26434/che...

In this work, we investigate inverse-temperature expansions of magnetic properties of paramagnetic systems in a very general setting.

#TheoChem #CompChem #NMR (1/2)

I have an open PhD position. The exact topic is negotiable and can range from implementing new quantum-chemical methods in @orca-qc-official.bsky.social to computational studies of open-shell molecules.
🔗 Details: www.langresearch.org/open-phd-fel...

Please share!

#PhDposition #CompChem

What I don't understand: Golding & Halton employ their model Hamiltonian in an entire LS term. States with same MS and different ML have different f-orbitals occupied. Likewise when switching the Ln(III) ion. Why should different f-orbital occupations lead to the same ligand spin density? (2/2)

Thanks for the answers!
What I am mainly confused about: the primary origin of spin density is the partial occupation of the 4f orbitals. Common wisdom is that they polarize the more diffuse metal-centered orbitals that participate in weak covalent bonding with the ligands. (1/2)

My questions are:
1) How exactly does the constant A relate to the microscopic quantum-chemical Hamiltonian and its eigenstates?
2) Why should A be similar for isostructural complexes containing different lanthanide(III) ions?

Any experts here on the theory of Fermi contact NMR shifts in lanthanide complexes? Most of the work on this topic can be traced back to Golding and Halton (1972). They assume that the hyperfine Hamiltonian can be expressed as A 𝗜⋅𝗦.
(1/2)

I found this copy of Wybourne's "Spectroscopic Properties of Rare Earths" in the @tuberlin.bsky.social library. I think it has aged very well for a book from 1965, and is full of interesting insights. Highly recommended for anyone interested in the electronic structure of lanthanide compounds.

Ever wondered why quantum-chemical equations look different in the atomic orbital (AO) basis? I just published a blog post explaining why — and how to easily derive them: www.langresearch.org?p=174

#QuantumChemistry #CompChem

The most innovative aspect of the implementation is the treatment of dipolar spin–spin coupling in a basis of configuration state function with a GUGA-like approach. I am happy to chat about this topic while still at #WATOC2025!

Treating Spin–Orbit Coupling and Spin–Spin Coupling in the Framework of the Iterative Configuration Expansion Selected CI Spin-adapted configuration state functions (CSFs) provide a compact many-electron basis for open-shell molecules. This basis is employed in one flavor of the recently introduced iterative configuratio...

I am excited to share our latest work on the implementation of magnetic properties for large active space selected CI wavefunctions in @orca-qc-official.bsky.social. Try it out in the new ORCA 6.1!

🔗: pubs.acs.org/doi/10.1021/...

#ORCA #CompChem #QC

On my way to #WATOC2025. I am excited about meeting old friends and learning new things!

I will present my poster about field-dependent NMR shifts in paramagnetic molecules on Tuesday evening (number 612). Looking forward to discuss this topic with you!

Theory of Field-Dependent NMR Shifts in Paramagnetic Molecules NMR chemical shifts depend on the applied magnetic flux density, and this becomes more and more important as stronger and stronger magnetic fields are becoming available. Herein we develop a theory of...

Did you know that NMR chemical shifts vary with the field strength of the spectrometer? We have developed a comprehensive theory explaining this phenomenon in paramagnetic molecules, now available online in JCTC @acs.org
🔗 Link: doi.org/10.1021/acs....

#QuantumChemistry #NMR