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rate_const_adv

esta.qeBag.rate_const_adv

rate constant calculations

for A* ---> B* kind of surface reaction or similar reaction

rate constant ~ r = A * exp ( -Ea/kbT )

where: A = ( kb * T/ h ) * (q_vib_TS / q_vib_A*) q = vib partition function = product_i (1/(1-expt(-h*nu_i / kbT)) )

read_freq_data(filename, freq_dft)

read freq data from file generated using qe phonon finite diff caclulations

input: 
filename: string, name of the file containing freq data
freq_dft: logical, whether dft calculated freq or expt or else..
output: 
vib_energies: array, filtered vib freq data (below 50 cm-1 freqs 
                are changed to 50 cm-1 by default)

q_partition(vib_energies_data, temp)

calculate the partition function based on given vib energies and temp

input: 
vib_energies: array  of length 3*natoms 
temp: scalar , temperature in K
output: 
q_partition: scalar,  parition function

get_rate_constant(q_part_is, q_part_ts, energy_barrier, temp)

get the rate constant of elementray steps

input: 
q_part_is: scalar, partition function for the initial state
q_part_ts: scalar, partition function for the transition state
energy_barrier: scalar, activation energy barrier going from initial to transition state in eV units
temp: scalar, tempature of the reaction in K units
output: 
rate_const: scalar, rate constant in s^(-1)