Formula prediction - Elemental heuristics

Description

This heuristics checks the formula's element counts as defined in Kind and Fiehn, BMC Bioinformatics 2007 (doi:10.1186/1471-2105-8-105).

Method parameters

H/C ratio
0.1 <= H/C ratio <= 6
NOPS/C ratios
N/C ratio <= 4, O/C ratio <= 3, P/C ratio <= 2, S/C ratio <= 3
Multiple element counts
if NOPS all > 1 then N< 10, O < 20, P < 4, S < 3
if NOP all > 3 then N < 11, O < 22, P < 6
if OPS all > 1 then O < 14, P < 3, S < 3
if PSN all > 1 then P < 3, S < 3, N < 4
if NOS all > 6 then N < 19 O < 14 S < 8