# ====================================
# Unit Conversion & Physical Constants
# ====================================

# Force constants from Jaguar frequency (mdyn A**-1) to au.
force_conversion = 15.569141
# The infamous fred for reduced normal coordinates
fred = 0.0911355
# Normal mode frequencies in cm-1
hfreq_cm = 5140.48
# Electron Volts to wave numbers (cm^-1)
ev_to_cm = 8065.54
# Hartree to Electron Volts
au_to_ev = 27.211396
# Hartree to kJ mol**-1.
au_to_kjmol = 2625.5
# Hartree to J
au_to_j = 4.359744650e-18
# Hartree to kcal mol**-1
au_to_kcalmol = 627.51
# kcal mol**-1 to Electron Volts
kcal_mol_to_ev = 0.0434
# Bohr to Angstrom
bohr_to_ang = 0.5291772086
# au to mdyn A**-1
au_to_mdyna = 15.569141
# The Hartree energy 
E_h = 4.35974434e-18
# The Avogadro constant
Na = 6.02214179e23
# The gas law constant in J/mol K
R = 8.314472
# The Bohr radius in m
a0 = 5.2917721092e-11
# The atomic mass unit in kg
amu = 1.660538921e-27
# The speed of light in a vacuum in m/s
c = 299792458
# The elementary charge in C
e = 1.602176565e-19
# The Planck constant in J.s
h = 6.62606896e-34
# Reduced h [Note the unusual units, inspired by spectroscopy work]
hbar = 0.6582  # eV - fs
# Boltzmann constant
kb = 8.6173324e-05  # eV K-1
# Hessian conversion factor
# hess_fact = (au_to_ev)/(bohr_to_ang**2)
hess_fact = au_to_ev

