Chemical Physics physics.chem-ph

A Swiss Army knife is simple: one handle, many blades, each for its own task. Grab what you need and get to work. In materials science, graph neural networks have long resembled a scattered set of tools: MEGNet sat in the TensorFlow drawer, M3GNet in the PyTorch drawer, and CHGNet in a separate box with its own scripts.

Water is the gold standard for life. We search for its traces on Mars, in icy moons, and in the atmospheres of distant planets. But what if life doesn't need water? On a warm rocky exoplanet with a thin atmosphere, water would evaporate within hours.

On a two-by-two-millimeter diamond plate, an entire orchestra of forty-nine violins fits. Each string is tuned to its own note, its own DNA fragment. When the right melody enters the hall, the string responds, and the conductor hears a clean sound. That conductor is a quantum sensor hidden within the diamond itself.

Inside every living cell, chemical transformations are constantly taking place. Some of them create unstable particles whose electrons behave like paired magnets. Their interaction resembles a dance: each movement of the pair responds to external magnetic fields, as if to a changing rhythm.

A virus of carbon life is a tiny container where the hereditary thread is compressed to the limit, like spaghetti in a tightly packed pot.

Science is a vast kitchen where scientist-cooks seek new recipes. Once, they sifted ingredients by hand; now artificial intelligence, a seasoned chef, lends a hand. AI memorizes millions of flavors and suggests surprising pairings: through information search, the algorithm uncovers hidden patterns.

Drug design is like picking a lock: the drug molecule must fit precisely into the target protein. But the lock is submerged in water, and the fluid’s friction alters the fit. Classical calculations account for this by modeling the key dissolving into the solvent for hours per attempt.

Electrons — tiny particles in molecules — constantly maneuver, avoiding collisions like passengers during rush hour. To calculate their behavior, scientists set a personal distance rule: a mathematical function that indicates how close one electron can get to its neighbor.

A bacterium in a drop of water doesn't just swim: it probes the space around it, decides where to turn, and finds its way out of a tangled maze. Artificial microscopic swimmers haven't been able to do that until now: they had to be led by the hand, with signals sent from outside.

You need to sift through millions of keys to find the one that unlocks the lock of a disease. Each key is a molecule, and the lock is a protein in our body. Checking each key manually is impossible, so chemists use computer models that predict how a molecule will behave in reality. Until recently, accurate calculations took hours or days on powerful computers. The new tool AceFF does it in seconds.

In a narrow slit between two plates, ions don't behave like free particles but like a crowd in a packed bus: pressed tightly together, they form dense clusters. This very property, the ability of ions to bunch up in extremely confined spaces, underpins a new mechanism for controlling ion transport. Researchers studied ion behavior in two-dimensional nanochannels just a few atoms wide.

An ordinary neural network for quantum chemistry is like a student who learns from mistakes but keeps tripping over the same spot. It crawls toward the right answer, is sensitive to settings, and often loses stability. For the fluorine molecule, the new method sped up calculations by 17,900 times compared to the popular Adam method.

In every handful of fertile soil, there are bacteria that do something no factory can: they take nitrogen straight from the air and turn it into fertilizer. The secret lies in the enzyme nitrogenase, and its working core, a cluster of iron and molybdenum atoms, looks like a tiny factory floor. Chemists have long tried to understand how this factory works from the inside.

In every leaf, in the light, a factory works that splits water into oxygen and hydrogen. The oxygen goes into the air we breathe, and the plant uses the hydrogen for food. The heart of this factory is a protein complex with four manganese atoms and one calcium atom.

Perovskite crystals are building blocks where metal atoms and halogens arrange into a neat lattice. Swap one halogen for another, and the crystal glows in a different color. But there's a catch: chlorine and iodine don't like to be neighbors in the same lattice, and in large crystals the mixture separates into distinct zones, like oil and water in a glass.

A graphene sheet is placed in a solution of sodium sulfate — an ordinary salt, similar to table salt. Near the surface, water stops being uniform: it arranges into layers, like a stack of pancakes. Between and within these layers, ions, charged particles from the dissolved salt, distribute themselves.

A piggy bank where coins slip in easily but can only be retrieved by smashing it. Something similar happens with a new material for sodium batteries. It readily accepts sodium ions during charging, but during discharge, it gives back almost nothing.

A magnetic compass in a test tube sounds like a magic trick, but it's pure physics. In a solution of fumarate (a salt of malic acid), carbon-13 nuclei behave like tiny spinning tops.

In a glass of salty water, even if it sits perfectly still, something is always happening. Tiny salt particles, ions, float and collide, sending ripples through the water. These ripples are invisible, but they create a force that attracts or repels nearby objects. Previously, it was thought that this force only acts over very short distances, as if it quickly fades out.

In the air of factory floors and laboratories, invisible solvent molecules drift. One of them, acetonitrile, has a faint smell, but at high concentrations it can harm health. Typical sensors for it are bulky and expensive, but here we have a thin crystalline film that responds on its own to the presence of vapor.

In the cold, sparse clouds of space, particles rarely meet, but sometimes an ion and a neutral molecule pass close enough to stick together. As they do, they emit light, like a muted flash carrying away excess energy. This process is called radiative association, and it is responsible for the formation of many molecules in interstellar space.

In the Large Hadron Collider's detector, each proton collision leaves thousands of points — tracks of flying particles. A neural network learned to spot patterns in this scatter and predict what happened at the moment of impact.

Dissolve a few salts and formaldehyde in a glass of water. After a while, the liquid spontaneously separates: droplets with membranes appear, like tiny bubbles. Inside each droplet, chemical transformations occur, and the droplet itself grows, absorbing material from the surrounding solution. These droplets are not just bubbles.

When a molecule absorbs light, it doesn't just heat up: it transitions into a special, excited state. Its electrons rearrange, like musicians who, after a loud chord, start playing a new melody.

In the air we breathe, invisible chemical events are constantly unfolding. One of them is the birth and instant death of a particle with the formula H₂COO. Known as an 'intermediate,' it appears for a split second when ozone molecules collide with organic compounds, then immediately shatters into simpler fragments.

A handful of lead sulfide nanocrystals coated with charged molecules spontaneously assembles into a perfect crystalline lattice. Each nanocrystal is like a brick just a few nanometers across, while the charged molecules on its surface act as the mortar.

When a guest molecule enters a host molecule, it's like a key going into a lock. But molecules don't have rigid shapes: they bend a little, charges on their surfaces attract or repel, and predicting exactly how they'll fit together has been very hard. DeepHostGuest learns from thousands of known host-guest pairs.

A catalyst is a substance that speeds up a chemical reaction without being consumed itself. The best catalyst is one where every metal atom counts: the finer the particles, the more atoms are on the surface and the more active the material.

In a freezer, ordinary water turns to ice, but in living cells, such ice is a disaster: sharp crystals tear membranes apart like needles popping a balloon. Scientists who preserve cells for medicine have learned to avoid this calamity, but each method speaks its own language. A new study offers a common vocabulary — thermodynamics.

Making a new drug is like assembling a complex construction set, where each piece is a molecule and the instructions are written in an unfamiliar language. Chemists spend years finding the right combinations, but the slowest step isn't coming up with the idea: it's making it happen in a test tube. Synthesizing a molecule can take weeks, and any mistake sends the whole process back to square one.

Magnetic resonance is like a tuning fork that rings only at its own note. Each molecule has its own frequency, and from that you can tell what the molecule is and what state it's in. But previously, this tuning fork was listened to through a thick wall: the signal was blurred, and you couldn't make out the exact note.

A tiny speck of silver is born in a laser beam and immediately starts to grow — faster than you can blink. An ordinary microscope can't keep up with that speed, so until now no one had seen exactly how a nanoparticle appears and gains size. Now scientists have a tool that captures this 'movie' frame by frame.

An ordinary chemical reaction is like a ball rolling down a hill: it has one natural path. But if you place molecules in a tiny mirrored box, an optical microresonator, the light inside starts to interfere with the ball's motion. It can nudge it, hold it back, or even split its trajectory. In a new study, physicists traced exactly how this happens.

Salt in a glass of water is a crowd of charged particles. When there's plenty of water, each particle floats on its own, wrapped in a thick fur coat of water molecules. But as you keep adding salt, the water runs out for everyone, and the particles start seeking each other out. First, they stick together in pairs, then in larger clumps.

Porous zeolite minerals work like tiny sponges with holes of a strictly defined size. Through such holes, molecules of one kind pass while others get stuck: this is the basis for water purification, gas separation, and catalysis in petrochemistry.

If you dump a handful of coins on a table, the surface becomes bumpy. But add more coins, and they spread out into a flat layer on their own. Something similar happens when you deposit ultra-thin films of individual molecules onto a substrate. At first, islands appear on the surface — molecules cluster together like people in a queue. The film gets rougher and rougher.

The light from a single molecule is like a lone voice in a vast choir. To hear it, you need not a microphone but a delicate instrument that catches each photon and notes its arrival time.

Nitinol is a metal with a memory: compressed into a tiny tube, it springs back into shape inside a vessel and keeps it open. But simply inserting a stent isn't enough: it must not clog with clots. To prevent that, a drug is applied, which should be released slowly, like water from a sponge, not all at once.

In the cold clouds between the stars, where new suns are born, invisible chemical work is underway. Simple molecules collide, swap atoms, and assemble into chains that may later become part of planets. One such chain is the NCCO+ ion, made of nitrogen, two carbons, and oxygen.

Cometary ice slams into the young Earth. The pressure at the impact point is like stacking six aircraft carriers on your thumbnail. In the lab, such conditions are reproduced by squeezing a tiny sample between two rotating anvils. This time, adenosine monophosphate — one of the letters of future RNA — was placed under the anvils.