# Observing the 3D chemical bond and its energy distribution in a projected space

## TL;DR

This paper introduces a novel method for visualizing and analyzing chemical bonds and their energy distributions in a two-dimensional projected space, enabling detailed 3D bond analysis across different types of materials.

## Contribution

The authors present a new approach to analyze chemical bonds in a condensed charge density, allowing for objective identification of bond regions and energy distribution in a projected space.

## Key findings

- Bond silhouettes can be reverse-projected to reveal 3D bonding regions.
- The method applies to both metallic and covalent bonds, showing formation and structure.
- It reproduces known organic chemistry results from charge density data.

## Abstract

Our curiosity-driven desire to "see" chemical bonds dates back at least one-hundred years, perhaps to antiquity. Sweeping improvements in the accuracy of measured and predicted electron charge densities, alongside our largely bondcentric understanding of molecules and materials, heighten this desire with means and significance. Here we present a method for analyzing chemical bonds and their energy distributions in a two-dimensional projected space called the condensed charge density. Bond "silhouettes" in the condensed charge density can be reverse-projected to reveal precise three-dimensional bonding regions we call bond bundles. We show that delocalized metallic bonds and organic covalent bonds alike can be objectively analyzed, the formation of bonds observed, and that the crystallographic structure of simple metals can be rationalized in terms of bond bundle structure. Our method also reproduces the expected results of organic chemistry, enabling the recontextualization of existing bond models from a charge density perspective.