qml.qchem.localize_normal_modes¶

localize_normal_modes(freqs, vecs, bins=[2600])[source]¶

Localizes vibrational normal modes.

The normal modes are localized by separating frequencies into specified ranges following the procedure described in J. Chem. Phys. 141, 104105 (2014).

Parameters

• freqs (list[float]) – normal mode frequencies in cm^-1

• vecs (TensorLike[float]) – displacement vectors for normal modes

• bins (list[float]) – List of upper bound frequencies in cm^-1 for creating separation bins . Default is [2600] which means having one bin for all frequencies between 0 and 2600 cm^-1.

Returns

A tuple containing the following:

• list[float] : localized frequencies

• TensorLike[float] : localized displacement vectors

• TensorLike[float] : localization matrix describing the relationship between original and localized modes.

Return type

tuple

Example

>>> freqs = np.array([1326.66001461, 2297.26736859, 2299.65032901])
>>> vectors = np.array([[[ 5.71518696e-18, -4.55642350e-01,  5.20920552e-01],
...                      [ 1.13167924e-17,  4.55642350e-01,  5.20920552e-01],
...                      [-1.23163569e-17,  5.09494945e-12, -3.27565762e-02]],
...                     [[-4.53008817e-17,  4.90364125e-01,  4.90363894e-01],
...                      [-1.98591028e-16,  4.90361513e-01, -4.90361744e-01],
...                      [-2.78235498e-18, -3.08350419e-02, -6.75886679e-08]],
...                     [[ 5.75393451e-17,  5.37047963e-01,  4.41957355e-01],
...                      [ 6.53049347e-17, -5.37050348e-01,  4.41959740e-01],
...                      [-5.49709883e-17,  7.49851221e-08, -2.77912798e-02]]])
>>> freqs_loc, vecs_loc, uloc = qml.qchem.localize_normal_modes(freqs, vectors)
>>> freqs_loc
array([1332.62008773, 2296.73455892, 2296.7346082 ])