The difficult problem that has plagued science for many years has been solved, creating a breakthrough in optoelectronics.
In 1825, Michael Faraday discovered the existence of benzene when condensing a glowing gas. For a long time, we understood the atomic structure of benzene, but since the 1930s, science has been arguing about the electronic structure of benzene. If you don’t know, in quantum chemistry, “electronic structure” is the state of motion of an electron in an electrostatic field created by many stationary nuclei.
Atomic structure of benzene.
Discovering the electronic structure of benzene, we will have the building blocks of the future of optoelectronic materials development.
The atomic structure of benzene is as follows: it is a ring consisting of 6 carbon atoms and 6 hydrogen atoms, attached in pairs. But the fact that benzene has 42 electrons makes studying its electronic structure difficult.
” The mathematical description of benzene’s electrons shows that it has up to 126 dimensions ,” said chemist Timothy Schmidt. “It means that this function has up to 126 coordinate values, 3 values for each electron out of 42. The electrons do not work independently, so it is not possible to split the function into 42 3-dimensional functions”.
According to researcher Schmidt, the computer’s answer is not easy to understand, so scientists have to find a way to get the answer.
The mathematical function describing the electron of benzene shows that it has up to 126 dimensions.
They had to use mathematics to describe the electronic structure of benzene, and the formula needed to account for all of the 126 dimensions needed. It sounds complicated, and the nature of the problem is really difficult; That’s why science has been arguing for decades. Some have even questioned whether the electrons in benzene really work to solve this difficult problem.
There are two ways of thinking: one side thinks that benzene works on the basis of valence theory , with normally active electrons (localized electrons, active in a certain range); the other side argues that benzene obeys the satellite molecular theory , the electrons are delocalized, out of bounds and reaching out to neighboring atoms.
Here’s the conundrum: neither of these theories explains the electronic structure of benzene.
So a new explanation was needed, and the technique of “Voronoi Metropolis dynamic sampling” gave researchers a way out. With algorithms that describe the wave function of a multi-electron system, they solved the difficult problem.
The new algorithm decomposes the electron dimensions into Voronoi diagrams , with each frame showing one electron coordinate, allowing the team to plot the wave function of the entire 126 dimensions. And then they discovered something strange, changed the way science thought about benzene.
Vonoroi diagram example.
Research shows that electrons will “avoid” each other whenever they have the opportunity, causing the energy inside the molecule to decrease, thereby making the benzene structure more stable than before .
“Essentially, this discovery connects previous assumptions about the chemistry of benzene, showing us that the two existing models describing benzene can fit together,” said Professor Schmidt. speak.
“ And now we also know how to observe electron correlation – that is, how electrons avoid each other. This has always been overlooked, as previous calculations only applied when the energy changed, not taking into account the electrical activity taking place inside .”
The new study was published in Nature.