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Table 2 Priors for implausible losses

From: Fragmentation trees reloaded

Probability

Loss type and molecular formulas

\(10^{-3}\)

Implausible losses: \(\hbox {C}_{2}\hbox {O}\), \(\hbox {C}_{4}\hbox {O}\), \(\hbox {C}_{3}\hbox {H}_{2}\), \(\hbox {C}_{5}\hbox {H}_{2}\), \(\hbox {C}_{7}\hbox {H}_{2}\)

\(\frac{1}{3^{ rdbe }}\)

Neutral losses with negative ring double bond equivalent RDBE

0.1

Nitrogen-only losses, carbon-only losses: for example, \(\hbox {N}_{5}\) or \(\hbox {C}_{3}\)

1

All other neutral losses

0.9

Common radical losses: \(\hbox {H}^{\cdot }\), \(\hbox {O}^{\cdot }\), \({}^{\cdot }\hbox {OH}\), \({}^{\cdot }\hbox {CH}_{3}\), \(\hbox {CH}_{3}\hbox {O}^{\cdot }\), \({}^{\cdot }\hbox {C}_{3}\hbox {H}_{7}\), \({}^{\cdot }\hbox {C}_{4}\hbox {H}_{9}\), \(\hbox {C}_{6}\hbox {H}_{5}\hbox {O}^{\cdot }\)

\(10^{-3}\)

All other radical losses

  1. For an edge (uv) with loss \(u-v\) let \(P_{\text{loss-impl}}(u,v)\) be the prior for \(u-v\) chosen according to this table. Expert knowledge and evaluation of FTs from SIRIUS2 resulted in the implausible losses listed here [41]. These losses should only very rarely (if ever) occur in a FT, so we manually select reduced priors