PFG is a parallel formula generator to calculate the possible elemental compositions for a given mass. PFG is implemented in C++. It can be compiled by MSVC and GCC easily and run smoothly in both Windows and Linux.
-h or --help The help screen.
-m mass Set mass.
-t tol Set tolerance to tol 'ppm' ( default 5 ).
-u unit Set unit of tol, could be 'Da' or 'ppm' (default ppm).
-c charge Set charge to be calculated.
-r rules Set rules to constrain formulas
-f file Set filename to stored the generated formulas (default is stdout).
--X a-b Set atom range a (min) to b (max) of element X.
some of the valid elements:
X key mass(6 decimals shown)
----------------------------------------------------
C --C 12.000000
13C --13C 13.003355
H --H 1.007825
D --D 2.014102
N --N 14.003074
15N --15N 15.000109
O --O 15.994915
P --P 30.973762
S --S 31.972071
F --F 18.998403
Cl --Cl 34.968853
Br --Br 78.918338
I --I 126.904468
Si --Si 27.976927
Na --Na 22.989770
K --K 38.963707
--agentformula af Set agent formula.
--agentcharge ac Set the charge of the agent formula.
PFG 'Mesuximide' -m 203.0946 -t 5 --C 0-20 --H 0-40 --O 0-5 --N 0-5 -f test.txt
the result were stored in the test.txt