VALD3 line lists include lines that are forbidden by quantum mechanical selection rules or lines that involve two-electron excitation (the so-called "autoionizing" lines). Such transitions are marked by a letter that follows the Accuracy field in the Long Format output. The table below explains the meaning of the letters:
Field content |
Transition type |
blank |
Allowed transition |
A |
Autoionizing transition |
B |
Forbidden: Electric quadrupole transition (E2) |
C |
Forbidden: Magnetic dipole transition (M1) |
D |
Forbidden: Magnetic quadrupole transition (M2) |
E |
Forbidden: Electric octupole transition (E3) |
F |
Forbidden: Magnetic octupole transition (M3) |