LightCone is a web-based molecular visualization and structure editing tool developed by QuantaBricks. It is designed to be user-friendly, allowing high-school students to engage with molecular structures without prior tutorials. The tool supports various features such as editing bond lengths, angles, and dihedrals, as well as fragment selection with rotation and translation. LightCone is permanently free and runs entirely in the browser, ensuring that no data ever leaves the user's device. The upcoming desktop version will add additional features like large-trajectory rendering and molecular orbital visualization.

https://lightcone.quanta-bricks.com

(here is the paper about it) 😉

https://www.nature.com/articles/s41557-026-02123-8

Want to try the new g-xTB on your ORCA (or stand-alone)?

Grab the development version binary here:
https://github.com/grimme-lab/g-xtb

Unpack it.

Inside your ORCA directory, back up your current otool_xtb:

cp otool_xtb otool_xtb.bkp

Replace it with the new xTB binary:

cp ../xtb otool_xtb

You are now ready to use it.

In your ORCA input, just add:

! XTB

%xtb
  XTBINPUTSTRING "--gxtb"
end

Million-atom all-electron quantum chemistry reaches biomolecular scale

A new *Communications Chemistry* paper reports an all-electron Hartree–Fock/divide-and-conquer framework applied to biomolecular systems with tens of millions of atoms and more than 150 million electrons. The result is not high-accuracy quantum chemistry: it uses a minimal basis and aggressive approximations. Its importance is different: it shows that whole-system approximate quantum-mechanical descriptors for huge biological assemblies are becoming technically feasible.

[https://www.nature.com/articles/s42004-026-02038-y](https://www.nature.com/articles/s42004-026-02038-y)

Registration is open for GPMLFF 2026 — a 3-day workshop on General-Purpose Machine-Learned Force Fields: in theory & practice. Researchers entering the field are especially welcome!

Lectures and hands-on tutorials with a great speaker lineup: Klaus-Robert Müller, Gabor Csányi, Stefan Chmiela, Leonardo Medrano Sandonas, Yury Lysogorskiy, Ilyes Batatia, Arslan Mazitov, Adil Kabylda

📅 13–15 July 2026
📍 Hybrid — Luxembourg (50 on-site) + online
✅ Free registration — sign up by 1 June: https://gpmlffworkshop.github.io/
🏆 Poster prizes from JACS, JCTC, and Chemical Science

Fun Fact of the Day

The Gaussian-and-plane-wave (GPW) strategy used in CP2K avoids explicit four-center integrals by mapping densities onto plane-wave grids while retaining localized Gaussian orbitals for the Kohn–Sham states. That hybridization is one major reason CP2K scales unusually well for condensed-phase DFT. 😉

ASH: a multi-scale, multi-theory modelling program ⚛️

Tired of being locked into one code's ecosystem? Meet ASH — a Python-based computational chemistry framework built around one elegant idea:

Separate the Hamiltonian from the job type.

Your QM/MM theory is one object. Your job (opt, freq, MD, scan, NEB...) is another. Mix and match freely.

What you can do:
- Single-point calculations
- Geometry optimizations
- Surface scans & relaxed PES
- Nudged Elastic Band (NEB) for reaction paths & TS
- Molecular dynamics
- Numerical frequencies
- QM/MM and ONIOM hybrid setups, built in minutes

Interfaces galore — drive your favorite code from a single Python script:
ORCA · xTB · CP2K · Psi4 · PySCF · ccpy · Dalton · MRCC · CFour · MNDO · TeraChem · QUICK · Gaussian · NWChem

Perfect for automating workflows, multi-scale modelling, and benchmarking across methods without rewriting half your pipeline.

🆓 Free & open-source on GitHub:
https://github.com/RagnarB83/ash

🚀 Try it live in Colab:
[ASH in Google Colab](https://colab.research.google.com/drive/11-FG7eTElCvcMNZiTIEXcdWjcR4YWRS-#scrollTo=ViPg1cGuck_a)

Ketcher 🧪

Ketcher is a free, open-source, web-based chemical structure editor for drawing molecules and reactions.

It includes:

• Fast 2D chemical structure drawing
• 3D structure visualization
• Template libraries
• Stereochemistry support
• Reaction drawing and atom-to-atom mapping
• R-group and S-group tools
• Structure cleanup
• CIP descriptor calculation
• Molecular formula and molecular weight calculation
• OCR for recognizing chemical structures from images
• Import/export support for Molfile, RXN, SMILES, CML, SDF, CDX/CDXML, InChI, InChIKey, and more
• SVG rendering for clean browser display
• Easy integration into custom web applications, including React-based projects

A serious tool for chemists, teachers, students, and developers. ⚗️

Stop paying for chemistry editors before checking what open source can already do. 🔓

Repository: https://github.com/epam/ketcher

Use it online: https://lifescience.opensource.epam.com/KetcherDemoSA/index.html

MOrbVis

A GPU-accelerated molecular orbital viewer for the browser. Load a Molden or Gaussian Cube file and interactively explore isosurfaces with WebGPU compute shaders. Also available as a standalone Windows desktop application.

Github: https://github.com/Yasuaki-Ito/morbvis

https://yasuaki-ito.github.io/morbvis/

MolTUI: a terminal molecular viewer for quickly inspecting geometries

Kalman Szenes from ETH Zurich built a GUI for molecular visualization...inside the terminal!

Supports:
1) Trajectories
2) Single and multiple XYZ files
3) Orbitals
4) Normal modes
5) Cube files
6) Molden Files
7) ORCA GBW Files and Hess formats

You can install it via pip

pip install moltui

Also, you can take a look to the GitHub repo here 👀👉: https://github.com/kszenes/moltui

Are you into Theoretical and Computational Chemistry? Are you Latin American?
Do you want to connect with other Latinxs in Comp Chem?

This is for you!

Varinia Bernales and Alán Aspuru-Guzik (The Matter Lab, University of Toronto) created an online community to enable Latin American theoretical and computational chemists, both within and outside Latin America, to connect, share ideas, and build collaborative networks.

The Matter Lab has broader plans for this website, including an upcoming internship opportunity in their lab, as well as workshops, webinars, and summer schools.

Stay tuned for updates on The Matter Lab's social media:

LinkedIn 👥: https://www.linkedin.com/company/the-matter-lab-uoft/
BlueSky 🦋: https://bsky.app/profile/thematterlab.bsky.social

More info in the link below:
🌎 https://latam.matterlab.world/

Fun fact of the day

In nonadiabatic dynamics, the sign of an electronic eigenvector is arbitrary. A wavefunction can flip phase between adjacent MD steps without changing any observable, but finite-difference nonadiabatic couplings will treat that sign flip as a huge artificial derivative unless the phases are corrected. That is why the new CP2K NAC framework explicitly includes phase correction.

open access

Chemical bonding concepts emerge naturally from maximally entangled atomic orbitals

Maximally entangled atomic orbitals provide a quantitative orbital-entanglement route to identify Lewis, multicenter, and aromatic bonding patterns beyond conventional localized-orbital pictures.

https://www.nature.com/articles/s41467-026-73527-w