vibrav.numerical.frequencies module

vibrav.numerical.frequencies.numerical_frequencies(delfq_plus, delfq_minus, redmass, nmodes, delta)[source]

Here we calculated the frequencies from the gradients calculated for each of the displaced structures along the normal mode. In principle this should give the same or nearly the same frequency value as that from a frequency calculation.

Parameters:

  • delfq_0 (numpy.ndarray) – Array that holds all of the information about the gradient derivative of the equlilibrium coordinates.

  • delfq_plus (numpy.ndarray) – Array that holds all of the information about the gradient derivative of the positive displaced coordinates.

  • delfq_minus (numpy.ndarray) – Array that holds all of the information about the gradient derivative of the negative displaced coordinates.

  • redmass (numpy.ndarray) – Array that holds all of the reduced masses. We can handle both a subset of the entire values or all of the values.

  • select_freq (numpy.ndarray) – Array that holds the selected frequency indexes.

  • delta (numpy.ndarray) – Array that has the delta values used in the displaced structures.

Returns:

frequencies (numpy.ndarray) –

Frequency array from the

calculation.