Kimika Teorikoa Lab

Join us for the Summer School in Biomolecular Simulations with AMBER #AMBER2026
amber2026.dipc.org

MD workflows, QM/MM, Free energy, ML potentials... 💻

Organized by
@xabierjota.bsky.social & Darrin York

📅 Dates: 13-17 July 2026
📍Donostia-San Sebastián (Spain)

Electronic structure origins of radical character in triangular fused acenes: sextet stabilization vs. antiaromaticity release Open-shell hydrocarbons are of great interest in molecular materials, yet their electronic structures remain challenging to describe. Here we investigate triangular acenes, formed by fusing three iden...

Check out the last collaborative work by David Casanova

@dipcehu.bsky.social

Electronic structure origins of radical character in triangular fused acenes: sextet stabilization vs. antiaromaticity release - now published in Organic Chemistry Frontiers pubs.rsc.org/en/content/a...

Limitations of quantum hardware for molecular energy estimation using VQE Variational quantum eigensolvers (VQEs) are among the most promising quantum algorithms for solving electronic structure problems in quantum chemistry, particularly during the noisy intermediate-scale...

Check out the latest by Abel Carreras and David Casanova, here with Román Orús
@dipcehu.bsky.social

doi.org/10.1039/D5CP...

Spin-Permutation Diabatization: A General Framework for Spin Localization and Exchange Coupling We present a spin-permutation diabatization strategy that transforms ab initio spin-pure eigenstates into spin-localized diabatic states, enabling direct mapping to spin-effective Hamiltonians without projection or orbital localization. The method provides both a real-space decomposition of electronic states in terms of localized spins and a straightforward evaluation of exchange couplings. Applications to several representative systems, including ethylene torsion, prototypical diradicals (benzynes, xylylenes, methylene), trimethylenebenzene triradical, singlet–triplet excited states of organic chromophores, and triplet-pair states in a tetracene dimer, demonstrate that the approach provides magnetic couplings and affords a clear physical interpretation of interacting spins. This general and conceptually transparent framework bridges ab initio electronic structure theory and spin models, and is expected to be especially valuable for systems with nontrivial distributions of unpaired electrons, such as delocalized or strongly correlated molecular magnets and spin-active chromophores.

Check the latest work by Alicia Omist and David Casanova, now available at JCTC from @acs.org
@dipcehu.bsky.social

pubs.acs.org/doi/full/10....

If you are an early-stage career scientist 🧑‍🔬 using biomolecular simulations the BioExcel Summer School is for you!

Running since 2018 it always receives outstanding reviews

Apply here ➡️ bioexcel.eu/4ooy

Deadline for applications: 1st February!

#training #molecularsimulations #community

Localized Molecular Orbitals for Single Excitation Theories This figure illustrates the workflow for analyzing excited states using localized molecular orbitals (LMOs). Canonical molecular orbitals (CMOs) from self-consistent field calculations are transforme...

Check out the latest collaborative effort by David Casanova, now available at J. Comput. Chem.
@dipcehu.bsky.social

onlinelibrary.wiley.com/doi/10.1002/...

Big day for the group!

We've got a new PhD!👏👏

Today, Aitor Díaz Andrés defended his #PhD thesis 'From electronic coupling to exciton dynamics: Modeling photophysical processes in rubrene solids', carried out under the supervision of David Casanova (DIPC, Ikerbasque)

Zorionak Aitor! 🥳

Assessing Second-Order Perturbative Corrections to Restricted Active Space CI for Valence Excitations in Organic Molecules We benchmark second-order perturbative corrections to the Restricted Active Space Configuration Interaction in the hole and particle approximation, RAS(h,p), for valence singlet and triplet excitation...

Check out the latest by David Casanova from our lab
@dipcehu.bsky.social

Assessing Second-Order Perturbative Corrections to Restricted Active Space CI for Valence Excitations in Organic Molecules | now available The Journal of Physical Chemistry A

pubs.acs.org/doi/full/10....

📣 we are hiring!

We are looking for candidates for a fully funded PhD position at EHU to study organic radicals and charge-to-spin conversion mechanisms using computational chemistry methods @ec.europa.eu
👩‍🔬🧑‍🔬

📅 Deadline: April 17

👇 Details below, please RT

www.danielreta.com/phd-computat...

Here we are, the moment we’ve all been waiting for.
📢 Registration & Abstract Submission Now Open!
Register before 15 March 2026 to secure the early bird fee!
📅 Abstract submission is open until 31 May 2026.
Find all details here: dft2026.com
#DFT2026

Fresh news! 📷 Registration & Abstract Submission for #DFT2026 Now Open!
Register before 15 March 2026 to secure the early bird fee!
Abstract submission is open until 31 May 2026.
Find all details here:
dft2026.com

Excited to share a fantastic set of sessions coming up at the MDDB Conference:

Day 1: Large-scale MD simulations
Day 2: MD kinetics and free energy / Industrial applications of MD
Day 3: Innovative applications of MD to biological systems

Explore more and register at ➡️ mddbr.eu/conference/

#MDDB

Check out this piece on the latest collaborative work by Elisa Jiménez Izal, Txema Mercero and Ramón Bergua from our lab
@dipcehu.bsky.social
@ehu.eus

🧑‍🎓We have a new PhD!!!! 🥳
Congrats to the great Antonio Cebreiro, who today defended his PhD, supervised by David Casanova

@dipcehu.bsky.social

Check out our latest, where we investigate the molecular origin of differences between Lys and Arg and their roles in biomolecular #condensates

@dipcehu.bsky.social

www.biorxiv.org/content/10.1...

Multiscale modelling of liquid-liquid and liquid-solid transitions in biomolecular condensates YouTube video by Donostia International Physics Center

Last week, we were lucky to have Jorge Reñé Espinosa from
@ucm.es visiting us at UPV-EHU and @dipcehu.bsky.social

If you missed his talk, here is the recording for your delight 👇
www.youtube.com/watch?v=ibsJ...

Happening in ~1 hour 👇

Pruned-ADAPT-VQE: Compacting Molecular Ansätze by Removing Irrelevant Operators The adaptive derivative-assembled problem-tailored variational quantum eigensolver (ADAPT-VQE) is one of the most widely used algorithms for electronic structure calculations in quantum computers. It adaptively selects operators based on their gradient, constructing ansätze that continuously evolve to match the energy landscape, helping avoid local traps and barren plateaus. However, this flexibility in reoptimization can lead to the inclusion of redundant or inefficient operators that have almost zero parameter value, barely contributing to the ansatz. We identify three phenomena responsible for the appearance of these operators: poor operator selection, operator reordering, and fading operators. In this work, we propose an automated, cost-free refinement method that removes unnecessary operators from the ansatz without disrupting convergence. Our approach evaluates each operator after ADAPT-VQE optimization by using a function that considers both its parameter value and position in the ansatz, striking a balance between eliminating low-coefficient operators while preserving the natural reduction of coefficients as the ansatz grows. Additionally, a dynamic threshold based on the parameters of recent operators enables efficient convergence. We apply this method to several molecular systems and find that it reduces ansatz size and accelerates convergence, particularly in cases with flat energy landscapes. The refinement process incurs, at most, a small additional computational cost and consistently improves or maintains ADAPT-VQE performance.

Check out the latest by David Casanova and co-workers

@dipcehu.bsky.social

*Pruned-ADAPT-VQE: Compacting Molecular Ansätze by Removing Irrelevant Operators*

Now available at JCTC

pubs.acs.org/doi/full/10....

Join our Cloud HD Video Meeting Zoom is the leader in modern enterprise cloud communications.

Condensate aficionados, this week, do not miss Jorge Reñe Espinosa's talk at @dipcehu.bsky.social

Friday 26 September: 12:00 PM CET

Zoom: dipc-org.zoom.us/j/97796482927
YouTube: youtube.com/live/ibsJcLv...

Eduard Matito and Mario Piris from our lab presenting their recent work at QVEST2025 at Schloss Ringberg
@dipcehu.bsky.social
@ehu.eus

Programa definitivo de Naukas Bilbao 15º Aniversario - Naukas Programa definitivo Naukas Bilbao 15 Aniversario (19 al 21 septiembre 2025)

¿Alguien en Bilbao hoy (sábado 20 de septiembre)?

No perderse la charla de la maravillosa @elirezabal.bsky.social 😍 (@theochemehu.bsky.social, @dipcehu.bsky.social) en @naukas.bsky.social #NAUKAS2025

⏰11:30 a 11:40 – 💫Elixabete Rezabal💫 – ¿Hueles vibraciones? 👃📳

naukas.com/2025/09/12/p...

Today #DIPCseminars 👇

📌 Kimika Teorikoa Seminar: Number of Bonds in Diatomic Molecules from Excited State Potential Energy Curves
👩‍🔬 Ishita Bhattacharjee, DIPC
🗓️ Sep 19, 10:00
🏫 DIPC Josebe Olarra Seminar Room

We are hiring, please RT! Lab manager in the #HEALIKICK #H2020 #HorizonEU project, responsible for biological sample processing and general lab aspects. Biotechnology, Biomedical engineering, Biomedicine or similar. @biogipuzkoa @Ikerbasque. More info & apply until 15/10 👉https://bit.ly/46tSKUl

Happening next week!

Our 23-September, special edition webinar will feature talks on topoisomerase inhibition, transmembrane signalling and membrane multilamellarity

Register here ➡️bioexcel.eu/ion8

Resolving Molecular Interactions in Protein Folding Trajectories with NCIPLOT Noncovalent interactions (NCIs) are fundamental to the structure, stability, and function of proteins. These interactions form complex networks that control how different protein regions relate to eac...

Out in its final form
pubs.acs.org/doi/10.1021/...

📣 @xabierjota.bsky.social and I are looking for candidates for a fully funded PhD position at UPV / EHU to study intrinsically disordered proteins using molecular simulations and computational chemistry calculations
👩‍🔬🧑‍🔬

📅 Deadline: October 1st

👇 Details below, please RT

A New Class of Diarylethene Compounds that Exhibit Turn‐On Emission: From Aggregation‐Induced Emission to Anti‐Kasha Emission A new class of diarylethene compounds containing backbone phosphine oxide groups are reported, exhibiting turn-on aggregation-induced emission. Side chain functionalization enabled emission color tun...

Check out the last collaborative effort by David Casanova and Claire Tonnelé from our laboratory
@dipcehu.bsky.social

advanced.onlinelibrary.wiley.com/doi/10.1002/...

Group picture in the last day of the 25th Anniversary Workshop of the TCCM Master ⚗️ 💻
Congratulations to the organisers and big thanks to all the participants for coming to Donostia-San Sebastián 👏👏👏👏

Y aquí va la distribución completa de proyectos:
- 2/3 partes de los proyectos tienen 50.000€ o menos por año. Esto no cambia.
- La financiación media por proyecto baja ligeramente (2%) respecto al PID2023.
- El porcentaje de éxito cae al 46% (49% en el PID2023).

La ciencia en España se estanca. 😕