2009A&A...494..729H

Electron-impact excitation collision strengths are required for the analysis and interpretation of stellar observations. This calculation aims to provide effective collision strengths for the MgV ion for a larger number of transitions and for a greater temperature range than previously available, using collision strength data that include contributions from resonances. A 19-state Breit-Pauli R-matrix calculation was performed. The target states are represented by configuration interaction wavefunctions and consist of the 19 lowest LS states, having configurations 2s²2p⁴, 2s2p⁵, 2p⁶, 2s²2p³3s, and 2s²2p³3p. These target states give rise to 37 fine-structure levels and 666 possible transitions. The effective collision strengths were calculated by averaging the electron collision strengths over a Maxwellian distribution of electron velocities. The non-zero effective collision strengths for transitions between the fine-structure levels are given for electron temperatures (T_e) in the range log₁₀T_e(K)=3.0-7.0. Data for transitions among the 5 fine-structure levels arising from the 2s²2p⁴ ground state configurations, seen in the UV range, are discussed in the paper, along with transitions in the EUV range - transitions from the ground state ³P levels to 2s2p⁵³P° levels. The 2s²2p⁴¹D-2s2p⁵¹P° transition is also noted. Data for the remaining transitions are available at the CDS.