//Example 3.7//
a=98.5;// Unit cell volume
b=0.117;//nm //nanometer //atomic radius of Silicon
V=a*b^3
mprintf("V = %f nm^3",V)
a1=8;//atoms
c=28.09;//gram //atomic mass of silicon
d=0.6023*10^24;//atoms //Avogardo's number
e=10^7;//nm/cm
P=(a1/V)*(c/d)*(e^3)
mprintf("\nP = %f g/cm^3",P)