LAUSR

High pressure Raman spectra of graphdiyne (GDY) have been studied up to 34.63 GPa. We found that sp-hybridized carbons in GDY are highly active and start to undergo a bonding change at around 5.2 GPa. Such a bonding change affects the C-C stretching vibration of sp2 hexagon rings in GDY, leading to an anomaly in the corresponding G-band pressure coefficient. A three-dimensional sp2 structure is proposed to form via pressure-induced interlayer cross-linking of sp carbons in GDY and is stable up to at least 34.63 GPa. Our study presents an important example in the study of graphyne family under pressure.High pressure Raman spectra of graphdiyne (GDY) have been studied up to 34.63 GPa. We found that sp-hybridized carbons in GDY are highly active and start to undergo a bonding change at around 5.2 GPa. Such a bonding change affects the C-C stretching vibration of sp2 hexagon rings in GDY, leading to an anomaly in the corresponding G-band pressure coefficient. A three-dimensional sp2 structure is proposed to form via pressure-induced interlayer cross-linking of sp carbons in GDY and is stable up to at least 34.63 GPa. Our study presents an important example in the study of graphyne family under pressure.