The forces holding diiodine molecules in the crystal are modest, and liquid iodine is not stable at ordinary temperatures and pressures, so that solid iodine sublimes to give a rather large concentration of diatomic molecules in the vapor phase. (religion-online.org)
In practice, mono - atomic and symmetrical diatomic gas molecules have negligible emission / absorption at most wavelengths including thermal infrared. (scienceofdoom.com)
Under normal conditions hydrogen is a gas consisting of diatomic molecules. (sciencedaily.com)