On the "input.txt" file, you can specify the material according to the following:
Line 1: name of the material
Line 2: fraction by mole or weight: [m/w]
Line 3: the material composition in terms of element symbols (E*) and fractions (F**): [ F1E1 + F2E2 + ... + FnEn ]
Line 4: density of the material in g/cm^3 (***)
Line 5: the energy range in MeV, must be from the list of common energies (****). Maximum range: 0.001-100000
Line 6: option to view plots: [yes/no] or [y/n]

Example:
water
w
11.1898H + 88.8102O
1
0.01-1000
yes

After saving the changes (Ctrl + s), you can run the program by double clicking on "GRASP.exe".
When the program finishes, you can save the data as an Excel file. Saved Excel files are found in the folder "saved_data".
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*	Symbols are case sensitive. Only elements 1-100 are available.
**	If the fractions don't add up to 1, they will be renormalized.
***	Density is required to calculate LAC and its derivatives. MAC and Zeff are independent of density, but Line 4 should NOT be left blank.	
****	List of common energies (MeV):
[0.001, 0.0015, 0.002, 0.003, 0.004, 0.005, 0.006, 0.008, 0.01, 0.015, 0.02, 0.03, 0.04, 0.05, 0.06, 0.08, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8, 1, 1.022, 1.25, 1.5, 2, 2.044, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 22, 24, 26, 28, 30, 40, 50, 60, 80, 100, 150, 200, 300, 400, 500, 600, 800, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 8000, 10000, 15000, 20000, 30000, 40000, 50000, 60000, 80000, 100000]