pymatgen.analysis.nmr module¶

class ChemicalShielding[source]¶

Bases: pymatgen.core.tensors.SquareTensor

This class extends the SquareTensor to perform extra analysis unique to NMR Chemical shielding tensors

Three notations to describe chemical shielding tensor (RK Harris; Magn. Reson. Chem. 2008, 46, 582–598; DOI: 10.1002/mrc.2225) are supported.

Authors: Shyam Dwaraknath, Xiaohui Qu

Create a Chemical Shielding tensor. Note that the constructor uses __new__ rather than __init__ according to the standard method of subclassing numpy ndarrays.

Parameters:	cs_matrix (1x3 or 3x3 array-like) – the 3x3 array-like representing the chemical shielding tensor or a 1x3 array of the primary sigma values corresponding to the principal axis system vscale (6x1 array-like) – 6x1 array-like scaling the voigt-notation vector with the tensor entries

HaeberlenNotation¶: alias of HaeberlenNotion

class MarylandNotation(sigma_iso, omega, kappa)¶

Bases: tuple

Create new instance of MarylandNotation(sigma_iso, omega, kappa)

kappa¶: Alias for field number 2

omega¶: Alias for field number 1

sigma_iso¶: Alias for field number 0

class MehringNotation(sigma_iso, sigma_11, sigma_22, sigma_33)¶

Bases: tuple

Create new instance of MehringNotation(sigma_iso, sigma_11, sigma_22, sigma_33)

sigma_11¶: Alias for field number 1

sigma_22¶: Alias for field number 2

sigma_33¶: Alias for field number 3

sigma_iso¶: Alias for field number 0

classmethod from_maryland_notation(sigma_iso, omega, kappa)[source]¶

haeberlen_values¶

the Chemical shielding tensor in Haeberlen Notation

Type:	Returns

maryland_values¶

the Chemical shielding tensor in Maryland Notation

Type:	Returns

mehring_values¶

the Chemical shielding tensor in Mehring Notation

Type:	Returns

principal_axis_system¶: Returns a chemical shielding tensor aligned to the principle axis system so that only the 3 diagnol components are non-zero

class ElectricFieldGradient[source]¶

Bases: pymatgen.core.tensors.SquareTensor

This class extends the SquareTensor to perform extra analysis unique to NMR Electric Field Gradient tensors in units of V/Angstrom^2

Authors: Shyam Dwaraknath, Xiaohui Qu

Create a Chemical Shielding tensor. Note that the constructor uses __new__ rather than __init__ according to the standard method of subclassing numpy ndarrays.

Parameters:	efg_matrix (1x3 or 3x3 array-like) – the 3x3 array-like representing the electric field tensor or a 1x3 array of the primary values corresponding to the principal axis system vscale (6x1 array-like) – 6x1 array-like scaling the voigt-notation vector with the tensor entries

V_xx¶

V_yy¶

V_zz¶

asymmetry¶

(V_yy - V_xx)/V_zz

Type:	Asymmetry of the electric field tensor defined as

coupling_constant(specie)[source]¶

Computes the couplling constant C_q as defined in:: Wasylishen R E, Ashbrook S E, Wimperis S. NMR of quadrupolar nuclei in solid materials[M]. John Wiley & Sons, 2012. (Chapter 3.2)
C_q for a specific atom type for this electric field tensor:: C_q=e*Q*V_zz/h

h: planck’s constant Q: nuclear electric quadrupole moment in mb (millibarn e: elementary proton charge

Parameters:	specie – flexible input to specify the species at this site. Can take a isotope or element string, Specie object, or Site object
Returns:	the coupling constant as a FloatWithUnit in MHz

principal_axis_system¶: Returns a electric field gradient tensor aligned to the principle axis system so that only the 3 diagnol components are non-zero