Diamond Anvil Cell (IMAGE) Carnegie Institution for Science Caption This is an illustration of Ar(H2)2 in the diamond anvil cell. The arrows represent different ways that spectroscopic tools study the effect of extreme pressures on the crystal structure and molecular structure of the compound. (For experts, the red arrow represents Raman spectroscopy, the black arrow represents synchrotron x-ray diffraction, and the gray arrow represents optical absorption spectroscopy.) Credit Image courtesy of Cheng Ji. Usage Restrictions With credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.