Atomic and nuclear properties of materials:
Polymethylmethacrylate (acrylic, [CH₂C(CH₃)(COOCH₃)]_n)

Quantity	Value	Units	Value	Units
<Z/A>	0.53937
Density	1.19	g cm-3
Mean excitation energy	74.0	eV
Minimum ionization	1.929	MeV g-1cm2	2.296	MeV cm-1
Nuclear collision length	58.1	g cm-2	48.79	cm
Nuclear interaction length	82.8	g cm-2	69.54	cm
Pion collision length	85.5	g cm-2	71.86	cm
Pion interaction length	114.7	g cm-2	96.39	cm
Radiation length	40.55	g cm-2	34.07	cm
Critical energy	85.79	MeV (for e-)	83.51	MeV (for e+)
Molière radius	10.02	g cm-2	8.422	cm
Plasma energy	23.09	eV
Muon critical energy	1107.	GeV
Index of refraction (@ STP, Na D)	1.49

Composition:

Elem	Z	Atomic frac*	Mass frac*
H	1	8.00	0.080538
C	6	5.00	0.599848
O	8	2.00	0.319614
* calculated from mass fraction data.

Explanation of some entries
For muons, dE/dx = a(E) + b(E) E. Tables of b(E): PS PDF TEXT
Table of muon dE/dx and Range: PS PDF TEXT