Orthohydrogen and Parahydrogen (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption Hydrogen molecules consist of two hydrogen atoms that share their electrons in a covalent bond. In an orthohydrogen molecule, both nuclei are spin up. In parahydrogen, one is spin up and the other spin down. The orthohydrogen molecule as a whole has spin one, but the parahydrogen molecule has spin zero. Credit Lawrence Berkeley National Laboratory Usage Restrictions None 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.