You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

UV/Vis spectra of subporphyrazines and subphthalocyanines with aluminum and gallium: a time-dependent DFT study. The UV/Vis spectra of selected substituted subporphyrazines (SubPz) and subphthalocyanines (SubPc) with aluminum and gallium as central atoms are analyzed through time-dependent DFT calculations in chloroform. The results are compared with previous results with boron as the central atom to analyze the photochemical properties of these two families of compounds on varying the metal along the same group. The absorptions of SubPz (Al, Ga) are redshifted or blueshifted with respect to SubPz (B) depending on the nature of the R substituents of the molecule, whereas the absorptions of SubPc (Al, Ga) structures are redshifted and with smaller energy gaps with respect to SubPc (B) for all kinds of R substituents. Looking at their absorption spectra, these systems with aluminum and gallium may also have, as in the case of boron, promising photochemical properties.
{"Chemical": ["chloroform", "subphthalocyanines", "Al", "subporphyrazines", "boron", "gallium", "aluminum", "SubPc", "SubPz", "Ga"]}