soprano.properties.nmr.dipolar

Implementation of AtomsProperties that relate to NMR dipole-dipole couplings

Classes

DipolarCoupling([name])	Produces a dictionary of dipole-dipole coupling constants for atom pairs in the system.
DipolarCouplingList([name])	Produces a list of DipolarCoupling objects for atom pairs in the system.
DipolarDiagonal([name])	Produces a dictionary of dipole-dipole tensors as eigenvalues and eigenvectors for atom pairs in the system.
DipolarEuler([name])	Produces a dictionary of dipole-dipole coupling tensor Euler angles for atom pairs in the system.
DipolarRSS([name])	Compute the Dipolar constant Root Sum Square for each atom in a system, including periodicity, within a cutoff.
DipolarTensor([name])	Produces a dictionary of dipole-dipole coupling tensors for atom pairs in the system.

class soprano.properties.nmr.dipolar.DipolarCoupling(name=None, **params)

Bases: AtomsProperty

Produces a dictionary of dipole-dipole coupling constants for atom pairs in the system. For each pair, the closest periodic copy will be considered. The constant for a pair of nuclei i and j is defined as:

\[d_{ij} = -\frac{\mu_0\hbar\gamma_i\gamma_j}{8\pi^2r_{ij}^3}\]

where the gammas represent the gyromagnetic ratios of the nuclei and the r is their distance. The full tensor of the interaction is then defined as

\[\begin{split}D_{ij} = \begin{bmatrix} -d_{ij} & 0 & 0 \\ 0 & -d_{ij} & 0 \\ 0 & 0 & 2d_{ij} \\ \end{bmatrix}\end{split}\]

where the z-axis is aligned with \(r_{ij}\) and the other two can be any directions in the orthogonal plane.

Parameters:

• sel_i (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling. By default is None (= all of them).

• sel_j (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling with the ones in sel_i. By default is None (= same as sel_i).

• isotopes (dict) – dictionary of specific isotopes to use, by element symbol. If the isotope doesn’t exist an error will be raised.

• isotope_list (list) – list of isotopes, atom-by-atom. To be used if different atoms of the same element are supposed to be of different isotopes. Where a ‘None’ is present will fall back on the previous definitions. Where an isotope is present it overrides everything else.

• self_coupling (bool) – if True, include coupling of a nucleus with its own closest periodic copy. Otherwise excluded. Default is False.

• block_size (int) – maximum size of blocks used when processing large chunks of pairs. Necessary to avoid memory problems for very large systems. Default is 1000.

• isonuclear (bool) – if True, only compute couplings between nuclei of the same element. Default is False.

Returns:

Dictionary of couplings in Hz and r_{ij} versors,

pointing from i to j, by atomic index pair.

Return type:

dip_dict (dict)

Initialize an AtomsProperty and set its parameters. The AtomsProperty instance can then be called with a structure as its only argument to get the property with the given parameters.

Parameters:

• name (str) – a name to give to this specific instance of the property (will be used to store it as array if requested)

• params – named arguments specific to this type of property

__call__(s, store_array=False, selection=None)

Calling the AtomsProperty returns the value of the property as extracted with the parameters of this specific instance.

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the given name for this instance

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

static extract(s, sel_i, sel_j, isotopes, isotope_list, self_coupling, block_size, isonuclear)

Extract the given property with given parameters from an Atoms object.

Parameters:

• s (ase.Atoms) – the structure from which to extract the property

• params – named arguments specific to this type of property

Returns:

the value of the property for the given structure and

parameters

Return type:

property

classmethod get(s, store_array=False, selection=None, **kwargs)

Extract the given property using the default parameters on an Atoms object s

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the default name for this property

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

mean(s, axis=None, weights=None, **kwargs)

Compute the mean of the property over a list of structures.

The default behaviours are: - For a list of scalars, compute the mean along the specified axis. - For a list of dictionaries, compute the mean for each key across all dictionaries. - For a list of NMRTensor objects, compute the mean using the NMRTensor.mean method. - For a list of arrays, convert to numpy array and then compute the mean along the specified axis.

Parameters:

• s (list[ase.Atoms] | AtomsCollection) – The structure or collection from which to extract the property.

• axis (int | None) – Axis along which the means are computed. If None, compute the mean of scalars.

• weights (np.ndarray | None) – An array of weights associated with the values. If specified, the weighted average will be computed. Must have the same shape as the property values.

• **kwargs – Additional arguments passed to the property’s get method.

Returns:

The mean value of the property for the given structures.

Return type:

dict | float | np.ndarray | NMRTensor

Raises:

• ValueError – If s is not a collection/list, if property values are None, or if there’s an incompatible shape for computing the mean.

• TypeError – If the property values are of a type that cannot be averaged.

class soprano.properties.nmr.dipolar.DipolarCouplingList(name=None, **params)

Bases: AtomsProperty

Produces a list of DipolarCoupling objects for atom pairs in the system. For each pair, the closest periodic copy will be considered.

See DipolarTensor for the definition of the dipolar tensor used.

Parameters:

• sel_i (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling. By default is None (= all of them).

• sel_j (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling with the ones in sel_i. By default is None (= same as sel_i).

• isotopes (dict) – dictionary of specific isotopes to use, by element symbol. If the isotope doesn’t exist an error will be raised.

• isotope_list (list) – list of isotopes, atom-by-atom. To be used if different atoms of the same element are supposed to be of different isotopes. Where a ‘None’ is present will fall back on the previous definitions. Where an isotope is present it overrides everything else.

• self_coupling (bool) – if True, include coupling of a nucleus with its own closest periodic copy. Otherwise excluded. Default is False.

• block_size (int) – maximum size of blocks used when processing large chunks of pairs. Necessary to avoid memory problems for very large systems. Default is 1000.

• rotation_axis (np.ndarray) – if present, return the residual dipolar tensors after fast averaging around the given axis. Default is None.

• isonuclear (bool) – if True, only compute couplings between nuclei of the same element. Default is False.

Returns:

List of DipolarCoupling objects.

Return type:

dip_list (list)

Initialize an AtomsProperty and set its parameters. The AtomsProperty instance can then be called with a structure as its only argument to get the property with the given parameters.

Parameters:

• name (str) – a name to give to this specific instance of the property (will be used to store it as array if requested)

• params – named arguments specific to this type of property

__call__(s, store_array=False, selection=None)

Calling the AtomsProperty returns the value of the property as extracted with the parameters of this specific instance.

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the given name for this instance

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

static extract(s, sel_i, sel_j, isotopes, isotope_list, self_coupling, block_size, rotation_axis, isonuclear)

Extract the given property with given parameters from an Atoms object.

Parameters:

• s (ase.Atoms) – the structure from which to extract the property

• params – named arguments specific to this type of property

Returns:

the value of the property for the given structure and

parameters

Return type:

property

classmethod get(s, store_array=False, selection=None, **kwargs)

Extract the given property using the default parameters on an Atoms object s

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the default name for this property

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

mean(s, axis=None, weights=None, **kwargs)

Compute the mean of the property over a list of structures.

The default behaviours are: - For a list of scalars, compute the mean along the specified axis. - For a list of dictionaries, compute the mean for each key across all dictionaries. - For a list of NMRTensor objects, compute the mean using the NMRTensor.mean method. - For a list of arrays, convert to numpy array and then compute the mean along the specified axis.

Parameters:

• s (list[ase.Atoms] | AtomsCollection) – The structure or collection from which to extract the property.

• axis (int | None) – Axis along which the means are computed. If None, compute the mean of scalars.

• weights (np.ndarray | None) – An array of weights associated with the values. If specified, the weighted average will be computed. Must have the same shape as the property values.

• **kwargs – Additional arguments passed to the property’s get method.

Returns:

The mean value of the property for the given structures.

Return type:

dict | float | np.ndarray | NMRTensor

Raises:

• ValueError – If s is not a collection/list, if property values are None, or if there’s an incompatible shape for computing the mean.

• TypeError – If the property values are of a type that cannot be averaged.

class soprano.properties.nmr.dipolar.DipolarDiagonal(name=None, **params)

Bases: AtomsProperty

Produces a dictionary of dipole-dipole tensors as eigenvalues and eigenvectors for atom pairs in the system. For each pair, the closest periodic copy will be considered.

Parameters:

• sel_i (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling. By default is None (= all of them).

• sel_j (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling with the ones i sel_i. By default is None (= same as sel_i).

• isotopes (dict) – dictionary of specific isotopes to use, by element symbol. If the isotope doesn’t exist an error will be raised.

• isotope_list (list) – list of isotopes, atom-by-atom. To be used if different atoms of the same element are supposed to be of different isotopes. Where a ‘None’ is present will fall back on the previous definitions. Where an isotope is present it overrides everything else.

• self_coupling (bool) – if True, include coupling of a nucleus with its own closest periodic copy. Otherwise excluded. Default is False.

• block_size (int) – maximum size of blocks used when processing large chunks of pairs. Necessary to avoid memory problems for very large systems. Default is 1000.

• isonuclear (bool) – if True, only compute couplings between nuclei of the same element. Default is False.

Returns:

Dictionary of dipolar eigenvalues (in Hz) and

eigenvectors, by atomic index pair.

Return type:

dip_tens_dict (dict)

Initialize an AtomsProperty and set its parameters. The AtomsProperty instance can then be called with a structure as its only argument to get the property with the given parameters.

Parameters:

• name (str) – a name to give to this specific instance of the property (will be used to store it as array if requested)

• params – named arguments specific to this type of property

__call__(s, store_array=False, selection=None)

Calling the AtomsProperty returns the value of the property as extracted with the parameters of this specific instance.

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the given name for this instance

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

static extract(s, sel_i, sel_j, isotopes, isotope_list, self_coupling, block_size, isonuclear)

Extract the given property with given parameters from an Atoms object.

Parameters:

• s (ase.Atoms) – the structure from which to extract the property

• params – named arguments specific to this type of property

Returns:

the value of the property for the given structure and

parameters

Return type:

property

classmethod get(s, store_array=False, selection=None, **kwargs)

Extract the given property using the default parameters on an Atoms object s

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the default name for this property

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

mean(s, axis=None, weights=None, **kwargs)

Compute the mean of the property over a list of structures.

The default behaviours are: - For a list of scalars, compute the mean along the specified axis. - For a list of dictionaries, compute the mean for each key across all dictionaries. - For a list of NMRTensor objects, compute the mean using the NMRTensor.mean method. - For a list of arrays, convert to numpy array and then compute the mean along the specified axis.

Parameters:

• s (list[ase.Atoms] | AtomsCollection) – The structure or collection from which to extract the property.

• axis (int | None) – Axis along which the means are computed. If None, compute the mean of scalars.

• weights (np.ndarray | None) – An array of weights associated with the values. If specified, the weighted average will be computed. Must have the same shape as the property values.

• **kwargs – Additional arguments passed to the property’s get method.

Returns:

The mean value of the property for the given structures.

Return type:

dict | float | np.ndarray | NMRTensor

Raises:

• ValueError – If s is not a collection/list, if property values are None, or if there’s an incompatible shape for computing the mean.

• TypeError – If the property values are of a type that cannot be averaged.

class soprano.properties.nmr.dipolar.DipolarEuler(name=None, **params)

Bases: AtomsProperty

Produces a dictionary of dipole-dipole coupling tensor Euler angles for atom pairs in the system. See the DipolarTensor property for details on the tensor.

Parameters:

• sel_i (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling. By default is None (= all of them).

• sel_j (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling with the ones in sel_i. By default is None (= same as sel_i).

• isotopes (dict) – dictionary of specific isotopes to use, by element symbol. If the isotope doesn’t exist an error will be raised.

• isotope_list (list) – list of isotopes, atom-by-atom. To be used if different atoms of the same element are supposed to be of different isotopes. Where a ‘None’ is present will fall back on the previous definitions. Where an isotope is present it overrides everything else.

• self_coupling (bool) – if True, include coupling of a nucleus with its own closest periodic copy. Otherwise excluded. Default is False.

• isonuclear (bool) – if True, only compute couplings between nuclei of the same element. Default is False.

• block_size (int) – maximum size of blocks used when processing large chunks of pairs. Necessary to avoid memory problems for very large systems. Default is 1000.

• rotation_axis (np.ndarray) – if present, return the residual dipolar tensors after fast averaging around the given axis. Default is None.

• convention (str) – ‘zyz’ or ‘zxz’ accepted - the ordering of the Euler angle rotation axes. Default is zyz

• passive (bool) – active or passive rotations. Default is active (passive=False)

• degrees (bool) – return the angles in degrees. Default is False

Returns:

Dictionary of tensors in Hz by atomic index pair.

Return type:

dip_dict (dict)

Initialize an AtomsProperty and set its parameters. The AtomsProperty instance can then be called with a structure as its only argument to get the property with the given parameters.

Parameters:

• name (str) – a name to give to this specific instance of the property (will be used to store it as array if requested)

• params – named arguments specific to this type of property

__call__(s, store_array=False, selection=None)

Calling the AtomsProperty returns the value of the property as extracted with the parameters of this specific instance.

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the given name for this instance

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

static extract(s, sel_i, sel_j, isotopes, isotope_list, self_coupling, isonuclear, block_size, rotation_axis, convention, passive, degrees)

Extract the given property with given parameters from an Atoms object.

Parameters:

• s (ase.Atoms) – the structure from which to extract the property

• params – named arguments specific to this type of property

Returns:

the value of the property for the given structure and

parameters

Return type:

property

classmethod get(s, store_array=False, selection=None, **kwargs)

Extract the given property using the default parameters on an Atoms object s

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the default name for this property

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

mean(s, axis=None, weights=None, **kwargs)

Compute the mean of the property over a list of structures.

The default behaviours are: - For a list of scalars, compute the mean along the specified axis. - For a list of dictionaries, compute the mean for each key across all dictionaries. - For a list of NMRTensor objects, compute the mean using the NMRTensor.mean method. - For a list of arrays, convert to numpy array and then compute the mean along the specified axis.

Parameters:

• s (list[ase.Atoms] | AtomsCollection) – The structure or collection from which to extract the property.

• axis (int | None) – Axis along which the means are computed. If None, compute the mean of scalars.

• weights (np.ndarray | None) – An array of weights associated with the values. If specified, the weighted average will be computed. Must have the same shape as the property values.

• **kwargs – Additional arguments passed to the property’s get method.

Returns:

The mean value of the property for the given structures.

Return type:

dict | float | np.ndarray | NMRTensor

Raises:

• ValueError – If s is not a collection/list, if property values are None, or if there’s an incompatible shape for computing the mean.

• TypeError – If the property values are of a type that cannot be averaged.

class soprano.properties.nmr.dipolar.DipolarRSS(name=None, **params)

Bases: AtomsProperty

Compute the Dipolar constant Root Sum Square for each atom in a system, including periodicity, within a cutoff.

Parameters:

• cutoff (float) – cutoff radius in Angstroms at which the sum stops. By default 5 Ang.

• isonuclear (bool) – if True, only nuclei of the same species will be considered. By default is False.

• isotopes (dict) – dictionary of specific isotopes to use, by element symbol. If the isotope doesn’t exist an error will be raised.

• isotope_list (list) – list of isotopes, atom-by-atom. To be used if different atoms of the same element are supposed to be of different isotopes. Where a ‘None’ is present will fall back on the previous definitions. Where an isotope is present it overrides everything else.

Returns:

dipolar constant RSS for each atom in the system

Return type:

dip_rss (np.ndarray)

Initialize an AtomsProperty and set its parameters. The AtomsProperty instance can then be called with a structure as its only argument to get the property with the given parameters.

Parameters:

• name (str) – a name to give to this specific instance of the property (will be used to store it as array if requested)

• params – named arguments specific to this type of property

__call__(s, store_array=False, selection=None)

Calling the AtomsProperty returns the value of the property as extracted with the parameters of this specific instance.

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the given name for this instance

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

static extract(s, cutoff, isonuclear, isotopes, isotope_list)

Extract the given property with given parameters from an Atoms object.

Parameters:

• s (ase.Atoms) – the structure from which to extract the property

• params – named arguments specific to this type of property

Returns:

the value of the property for the given structure and

parameters

Return type:

property

classmethod get(s, store_array=False, selection=None, **kwargs)

Extract the given property using the default parameters on an Atoms object s

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the default name for this property

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

mean(s, axis=None, weights=None, **kwargs)

Compute the mean of the property over a list of structures.

The default behaviours are: - For a list of scalars, compute the mean along the specified axis. - For a list of dictionaries, compute the mean for each key across all dictionaries. - For a list of NMRTensor objects, compute the mean using the NMRTensor.mean method. - For a list of arrays, convert to numpy array and then compute the mean along the specified axis.

Parameters:

• s (list[ase.Atoms] | AtomsCollection) – The structure or collection from which to extract the property.

• axis (int | None) – Axis along which the means are computed. If None, compute the mean of scalars.

• weights (np.ndarray | None) – An array of weights associated with the values. If specified, the weighted average will be computed. Must have the same shape as the property values.

• **kwargs – Additional arguments passed to the property’s get method.

Returns:

The mean value of the property for the given structures.

Return type:

dict | float | np.ndarray | NMRTensor

Raises:

• ValueError – If s is not a collection/list, if property values are None, or if there’s an incompatible shape for computing the mean.

• TypeError – If the property values are of a type that cannot be averaged.

class soprano.properties.nmr.dipolar.DipolarTensor(name=None, **params)

Bases: AtomsProperty

Produces a dictionary of dipole-dipole coupling tensors for atom pairs in the system. For each pair, the closest periodic copy will be considered. The coupling constant for a pair of nuclei i and j is defined as:

\[d_{ij} = -\frac{\mu_0\hbar\gamma_i\gamma_j}{8\pi^2r_{ij}^3}\]

where the gammas represent the gyromagnetic ratios of the nuclei and the r is their distance. The full tensor of the interaction is then defined as

\[D_{ij} = d_{ij}(3\hat{r}_{ij}\otimes \hat{r}_{ij}-\mathbb{I})\]

where \(\hat{r}_{ij} = r_{ij}/|r_{ij}|\) and the Kronecker product is used.

Parameters:

• sel_i (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling. By default is None (= all of them).

• sel_j (AtomSelection or [int]) – Selection or list of indices of atoms for which to compute the dipolar coupling with the ones in sel_i. By default is None (= same as sel_i).

• isotopes (dict) – dictionary of specific isotopes to use, by element symbol. If the isotope doesn’t exist an error will be raised.

• isotope_list (list) – list of isotopes, atom-by-atom. To be used if different atoms of the same element are supposed to be of different isotopes. Where a ‘None’ is present will fall back on the previous definitions. Where an isotope is present it overrides everything else.

• self_coupling (bool) – if True, include coupling of a nucleus with its own closest periodic copy. Otherwise excluded. Default is False.

• block_size (int) – maximum size of blocks used when processing large chunks of pairs. Necessary to avoid memory problems for very large systems. Default is 1000.

• rotation_axis (np.ndarray) – if present, return the residual dipolar tensors after fast averaging around the given axis. Default is None.

• isonuclear (bool) – if True, only compute couplings between nuclei of the same element. Default is False.

Returns:

Dictionary of NMRTensor objects in Hz by atomic index pair.

Return type:

dip_dict (dict)

Initialize an AtomsProperty and set its parameters. The AtomsProperty instance can then be called with a structure as its only argument to get the property with the given parameters.

Parameters:

• name (str) – a name to give to this specific instance of the property (will be used to store it as array if requested)

• params – named arguments specific to this type of property

__call__(s, store_array=False, selection=None)

Calling the AtomsProperty returns the value of the property as extracted with the parameters of this specific instance.

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the given name for this instance

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

static extract(s, sel_i, sel_j, isotopes, isotope_list, self_coupling, block_size, rotation_axis, isonuclear)

Extract the given property with given parameters from an Atoms object.

Parameters:

• s (ase.Atoms) – the structure from which to extract the property

• params – named arguments specific to this type of property

Returns:

the value of the property for the given structure and

parameters

Return type:

property

classmethod get(s, store_array=False, selection=None, **kwargs)

Extract the given property using the default parameters on an Atoms object s

Args:

s (ase.Atoms or AtomsCollection): the structure or collection

from which to extract the

property

store_array (bool): if s is a collection, whether to store the

resulting data as an array in the collection

using the default name for this property

selection (str): a selection string to filter the atoms or AtomSelection

Returns:

property: the value of the property for the given structure or

a list of values if a collection has been passed

mean(s, axis=None, weights=None, **kwargs)

Compute the mean of the property over a list of structures.

The default behaviours are: - For a list of scalars, compute the mean along the specified axis. - For a list of dictionaries, compute the mean for each key across all dictionaries. - For a list of NMRTensor objects, compute the mean using the NMRTensor.mean method. - For a list of arrays, convert to numpy array and then compute the mean along the specified axis.

Parameters:

• s (list[ase.Atoms] | AtomsCollection) – The structure or collection from which to extract the property.

• axis (int | None) – Axis along which the means are computed. If None, compute the mean of scalars.

• weights (np.ndarray | None) – An array of weights associated with the values. If specified, the weighted average will be computed. Must have the same shape as the property values.

• **kwargs – Additional arguments passed to the property’s get method.

Returns:

The mean value of the property for the given structures.

Return type:

dict | float | np.ndarray | NMRTensor

Raises:

• ValueError – If s is not a collection/list, if property values are None, or if there’s an incompatible shape for computing the mean.

• TypeError – If the property values are of a type that cannot be averaged.