No one will ever be able to see a purely mathematical construct such as a perfect sphere. But now, scientists using supercomputer simulations and atomic resolution microscopes have imaged the signatures of electron orbitals, which are defined by mathematical equations of quantum mechanics and predict where an atom's electron is most likely to be.
This article has been reviewed according to Science X's editorial process and policies . Editors have highlighted the following attributes while ensuring the content's credibility: AFM images of FePc and CoPc on a Cu(111) surface. a Experimental constant-height AFM frequency-shift images (V = 0 V, tip amplitude = 100 pm) using a CO tip at a tip height of −10 pm with respect to our 100 mV/100 pA STM set point. The two white dashed circles highlight the main differences between these two molecules—the central metal atom. b Glow-edges filtered experimental AFM image (based on a). c Simulated AFM images with a CO tip at a tip height of −10 pm (see Supplementary Information for the definition of tip height in simulation). Left panel: spin-polarized DFT calculations; right panel: spin-paired DFT calculations (indicated by a superscript *). On the midline, the orbital-like figures are the calculated total electron density differences between MPc and M*Pc (MPc–M*Pc). Yellow: positive, cyan: negative. Isovalue: 0.003 e–/bohr3. d Estimated width (in pm) of the central part of the MPcs based on the signal strength—I value. The white dashed arrow pointing from b to d indicates a zoomed-in image of the central part of the left FePc molecule. The white curves are calculated I values along the corresponding dashed axes. The blue arrows illustrate how we define the width of the square based on I values. Top panel: FePc (in blue), bottom panel: CoPc (in red). Each MPc has two widths and corresponds to two circles. The gap between the two dashed black lines (the highest red and lowest blue circles) shows a minimum difference of 30 pm. Credit: Nature Communications (2023). DOI: 10.1038/s41467-023-37023-9 Scientists at UT Austin, Princeton University, and ExxonMobil have directly observed the signatures of electron orbitals in two different transition-metal atoms, iron (Fe) and cobalt (Co) present in metal-phthalocyanines. Those signatures are apparent in the forces measured by…