In this context, 𝜌 𝑖 free represents the spherically averaged density of atom i in its free state, with i looping over all atoms in the system. It has been found that the isosurfaces of 𝛿𝑔 can reasonably reveal regions where prominent interatomic interactions occur. Unlike NCI and IRI, 𝛿𝑔 offers a controllable display of interactions with varying strengths. Generally, the stronger the interaction, the larger the 𝛿𝑔 value in the corresponding region. Due to this feature, when a large isovalue of 𝛿𝑔 is used, only strong interactions are revealed, whereas a small isovalue can display both strong and weak interactions. Additionally, IGM defines 𝛿𝑔 inter and 𝛿𝑔 intra functions, allowing for the separate display of interfragment and intrafragment interactions: