parahelium

parahelium

[‚par·ə′hē·lē·əm]
(atomic physics)
Those states of helium in which the spins of the two electrons are antiparallel, in contrast to orthohelium. Also spelled parhelium.
References in periodicals archive ?
Likewise, if the ground state electron is 'spin up', the excited electron must be 'spin down' to enable the transition, He* [right arrow] He + h v, again producing the identical He I lines from singlet state parahelium.