Note

Click here to download the full example code

# Calculate/Plot Nuclear Larmor Frequency

This example demonstrates how to use the tool to calculate the nuclear Larmor frequency.

## Get Magnetic Resonance Properties

DNPLab stores a dictionary called `gmrProperties`

with magnetic resonance properties of all nuclei of the periodic table. The dictionary is modeled after the Matlab function *gmr* written, and implemented by Mirko Hovrat. For more details see the detailed documentation of the dictionary. The dictionary stores the following parameters:

Spin Quantum Number

Gyromagnetic Ratio (Hz/T)

Nuclear Quadrupole Moment (fm^2, 100 barns)

Isotope Natural Abundance (%)

Relative Sensitivity with Respect to 1H at same B_{0}

(for nuclei with I > 1/2), and some more parameters. This dictionary can be used to provide nuclear properties in any calculation, it is also used by the DNPLab function `mr_properties`

.

To get started, first, setup the python environment:

```
import dnplab as dnp
import numpy as np
import matplotlib.pyplot as plt
```

Let's query some of the parameters:

**Proton Gyromagnetic Ratio**

```
print("v_L(1H) = ", dnp.mr_properties('1H'), "(Hz/T)")
```

```
v_L(1H) = 26.7522128 (Hz/T)
```

**Nirogen 14N nuclear spin quantum number**

```
print("I = ", dnp.mr_properties('14N','spin'))
```

```
I = 1
```

**Carbon 13 (13C) natural abundance**

```
print(dnp.mr_properties('13C','natAbundance'), " %")
spinQuatnumNumber = np.empty(121)
k = 0
for each in dnp.gmrProperties.keys():
spinQuatnumNumber[k] = dnp.gmrProperties[each][0]
k = k + 1
```

```
1.07 %
```

**Total running time of the script:** ( 0 minutes 0.002 seconds)