# How can I interpret the CH4+ structure?

I am trying to teach myself about Electron Ionization, and am very confused about the formation of the CH4+ Ion.

Do the dotted lines between the C and the H, and between the two Hydrogens indicate a resonance structure of sort? I have taken organic chemistry, but cannot wrap my head around this.

• – Mithoron Sep 3 '18 at 21:16
• Dotted lines indicate three center bonds, which can be viewed as a sort of resonance. – Mithoron Sep 3 '18 at 21:19

Another way to look at this structure is that the dashed lines represent multicenter bonding. A common example of multicenter bonding is diborane $\ce{B2H6}$. The structure of diborane features 3-center-2-electron bonds (often abbreviated 3c2e bonds - in this notation, a typical single sigma bond is a 2c2e bond) with two hydrogen atoms shared by both boron atoms:
These bonds in $\ce{CH4+}$ could be considered a 3-centered-3-electron bond as originally each C-H bond would have had two electrons. The radical cation is one electron short, so there are only three electrons shared between those three atoms.