Table 4.

Priors $P_{\text{frag-comm}}(f)$ for common fragments f

Molecular formula		Ion mass	Total intensity		Total count		$P_{\text{frag-comm}}$
Protonated	Neutral		GNPS	Agilent	GNPS	Agilent
C3H6N+	C3H5N	56.0495	0.00	93.63	0	392	2.40
C3H8N+	C3H7N	58.0651	0.67	100.53	4	323	2.59
${\text{C}}_5{\text{H}}_5^{+}$	C5H4	65.0386	0.00	83.35	0	530	2.14
${\text{C}}_4{\text{H}}_8{\text{N}}^{+}$	${\text{C}}_4{\text{H}}_7\text{N}$	70.0651	7.38	56.00	8	313	1.62
${\text{C}}_4{\text{H}}_{10}{\text{N}}^{+}$	${\text{C}}_4{\text{H}}_9\text{N}$	72.0808	0.00	72.92	0	179	1.87
${\text{C}}_6\text{H}{5}^{+}$	${\text{C}}_6{\text{H}}_4$	77.0386	1.00	139.35	3	720	3.60
${\text{C}}_6{\text{H}}_7^{+}$	${\text{C}}_6{\text{H}}_6$	79.0542	0.52	69.85	3	514	1.80
${\text{C}}_5{\text{H}}_{12}{\text{N}}^{+}$	${\text{C}}_5{\text{H}}_{11}\text{N}$	86.0964	0.92	71.08	5	128	1.85
${\text{C}}_7{\text{H}}_7^{+}$	${\text{C}}_7{\text{H}}_6$	91.0542	60.61	252.97	300	720	8.04
${\text{C}}_6{\text{H}}_6{\text{N}}^{+}$	${\text{C}}_6{\text{H}}_5\text{N}$	92.0495	3.92	76.12	31	185	2.05
${\text{C}}_6{\text{H}}_9{\text{O}}^{+}$	${\text{C}}_6{\text{H}}_8\text{O}$	97.0648	10.95	58.00	37	86	1.77
${\text{C}}_6{\text{H}}_{12}{\text{N}}^{+}$	${\text{C}}_6{\text{H}}_{11}\text{N}$	98.0964	8.73	74.93	66	139	2.14
${\text{C}}_8{\text{H}}_7^{+}$	${\text{C}}_8{\text{H}}_6$	103.0542	64.49	34.61	562	241	2.54
${\text{C}}_7{\text{H}}_5{\text{O}}^{+}$	${\text{C}}_7{\text{H}}_4\text{O}$	105.0335	50.43	47.64	178	100	2.51
${\text{C}}_8{\text{H}}_9^{+}$	${\text{C}}_8{\text{H}}_8$	105.0699	108.25	104.51	580	352	5.45
${\text{C}}_7{\text{H}}_7{\text{O}}^{+}$	${\text{C}}_7{\text{H}}_6\text{O}$	107.0491	62.41	53.68	320	187	2.98
${\text{C}}_8{\text{H}}_{11}^{+}$	${\text{C}}_8{\text{H}}_{10}$	107.0855	35.23	29.89	171	120	1.67
${\text{C}}_6{\text{H}}_6{\text{NO}}^{+}$	${\text{C}}_6{\text{H}}_5\text{NO}$	108.0444	23.05	48.66	64	76	1.84
${\text{C}}_7{\text{H}}_9{\text{O}}^{+}$	${\text{C}}_7{\text{H}}_8\text{O}$	109.0648	37.15	53.40	161	107	2.32
${\text{C}}_9{\text{H}}_7^{+}$	${\text{C}}_9{\text{H}}_6$	115.0542	73.68	43.35	618	262	3.00
${\text{C}}_9{\text{H}}_9^{+}$	${\text{C}}_9{\text{H}}_8$	117.0699	61.67	46.66	371	206	2.78
${\text{C}}_9{\text{H}}_{11}^{+}$	${\text{C}}_9{\text{H}}_{10}$	119.0855	51.94	40.94	265	190	2.38
${\text{C}}_8{\text{H}}_9{\text{O}}^{+}$	${\text{C}}_8{\text{H}}_8\text{O}$	121.0648	125.09	72.05	394	201	5.05
${\text{C}}_{10}{\text{H}}_8^{+}$	${\text{C}}_{10}{\text{H}}_7$	128.0621	51.79	13.98	305	98	1.69
${\text{C}}_{10}{\text{H}}_9^{+}$	${\text{C}}_{10}{\text{H}}_8$	129.0699	60.60	24.99	425	163	2.19
${\text{C}}_9{\text{H}}_8{\text{N}}^{+}$	${\text{C}}_9{\text{H}}_7\text{N}$	130.0651	75.54	31.39	343	159	2.74
${\text{C}}_{10}{\text{H}}_{11}^{+}$	${\text{C}}_{10}{\text{H}}_{10}$	131.0855	61.12	34.37	277	144	2.45
${\text{C}}_9{\text{H}}_{10}{\text{N}}^{+}$	${\text{C}}_9{\text{H}}_9\text{N}$	132.0808	58.68	21.70	216	99	2.06
${\text{C}}_8{\text{H}}_7{\text{O}}_2^{+}$	${\text{C}}_8{\text{H}}_6{\text{O}}_2$	135.0441	40.37	22.03	176	53	1.60
${\text{C}}_9{\text{H}}_{11}{\text{O}}^{+}$	${\text{C}}_9{\text{H}}_{10}\text{O}$	135.0804	42.95	32.87	221	121	1.94
${\text{C}}_{11}{\text{H}}_{11}^{+}$	${\text{C}}_{11}{\text{H}}_{10}$	143.0855	54.61	23.88	288	118	2.01
${\text{C}}_{10}{\text{H}}_{10}{\text{N}}^{+}$	${\text{C}}_{10}{\text{H}}_9\text{N}$	144.0808	61.59	20.67	220	99	2.11
${\text{C}}_{11}{\text{H}}_{13}^{+}$	${\text{C}}_{11}{\text{H}}_{12}$	145.1012	57.60	28.15	219	110	2.20
${\text{C}}_9{\text{H}}_8{\text{NO}}^{+}$	${\text{C}}_9{\text{H}}_7\text{NO}$	146.0600	62.09	7.40	242	52	1.78
${\text{C}}_{10}{\text{H}}_{11}{\text{O}}^{+}$	${\text{C}}_{10}{\text{H}}_{10}\text{O}$	147.0804	67.16	33.97	247	107	2.59
${\text{C}}_{11}{\text{H}}_{11}{\text{O}}^{+}$	${\text{C}}_{11}{\text{H}}_{10}\text{O}$	159.0804	47.36	17.07	230	84	1.65
${\text{C}}_{10}{\text{H}}_{10}{\text{NO}}^{+}$	${\text{C}}_{10}{\text{H}}_9\text{NO}$	160.0757	58.53	18.10	221	40	1.96
${\text{C}}_{13}{\text{H}}_9^{+}$	${\text{C}}_{13}{\text{H}}_8$	165.0699	54.17	36.32	255	163	2.32
${\text{C}}_{13}{\text{H}}_{11}^{+}$	${\text{C}}_{13}{\text{H}}_{10}$	167.0855	28.57	36.85	123	65	1.68
${\text{C}}_{12}{\text{H}}_{11}{\text{O}}^{+}$	${\text{C}}_{12}{\text{H}}_{10}\text{O}$	171.0804	44.97	28.37	164	62	1.88

Entry “ion mass” is the exact theoretical mass of the protonated fragment. Entries “GNPS/Agilent” indicate total sum of the peak intensities and total peak count of the fragment in the two datasets. Note that a particular fragment can be very common, yet have relatively small sum of peak intensities, because fragments peaks are consistently of small intensity