import numpy as np

j = np.complex(0, 1)
#SI units
um = 10**(-6)
c = 3*10**8
fs_si = 10**(-15)
mv_per_cm_si = 10**8

#atomic units
fs = 1000/24.2
mv_per_cm = 1/5140.0
w_per_cm2 = 1/(3.51*10**16)
ev = 1/27.21
angstrom = 1/0.529177
