Get the high order unit based Mass Defect
getmdh(mz, cus = c("CH2,H2"), method = "round")
numeric vector for exact mass
chemical formula or reaction
you could use `round`, `floor` or `ceiling`
high order Mass Defect with details
getmdh(getmass('C2H4'))
#> mz MD1 MD2
#> 1 28.0313 0 0