Table 1 Rank-2 Spherical tensors depending on choice of lab or rotating frame

From: SLEEPY: a comprehensive Python module for simulating relaxation and dynamics in nuclear magnetic resonance

 

\({\hat{T}}_{\mathrm{2,0}}\)

\({\hat{T}}_{2,\pm 1}\)

\({\hat{T}}_{2,\pm 2}\)

Spin-Field (LF)

\(\sqrt{\frac{2}{3}}{\hat{S}}_{z}\)

\(\frac{1}{2}{\hat{S}}^{\pm }\)

0

Spin-Field (RF)

\(\sqrt{\frac{2}{3}}{\hat{S}}_{z}\)

0

0

Spin-Spin (LF/LF)

\(\frac{1}{\sqrt{6}}\left[3{\hat{{\rm{S}}}}_{1{\rm{z}}}{\hat{{\rm{S}}}}_{2{\rm{z}}}-{\vec{\hat{{\rm{S}}}}}_{1}\cdot {\vec{\hat{{\rm{S}}}}}_{2}\right]\)

\(\mp \frac{1}{2}\left[{\hat{S}}_{1}^{\pm }{\hat{S}}_{2z}+{\hat{S}}_{1z}{\hat{S}}_{2}^{\pm }\right]\)

\(\frac{1}{2}{\hat{S}}_{1}^{\pm }{\hat{S}}_{2}^{\pm }\)

Spin-Spin (LF/RF)

\(\frac{2}{\sqrt{6}}{\hat{{\rm{S}}}}_{1{\rm{z}}}{\hat{{\rm{S}}}}_{2{\rm{z}}}\)

\(\mp \frac{1}{2}{\hat{S}}_{1}^{\pm }{\hat{S}}_{2z}\)

0

Spin-Spin (RF/LF)

\(\frac{2}{\sqrt{6}}{\hat{{\rm{S}}}}_{1{\rm{z}}}{\hat{{\rm{S}}}}_{2{\rm{z}}}\)

\(\mp \frac{1}{2}{{\hat{S}}_{1z}\hat{S}}_{2}^{\pm }\)

0

Spin-Spin (RF/RF, homonuclear)

\(\frac{1}{\sqrt{6}}\left[3{\hat{{\rm{S}}}}_{1{\rm{z}}}{\hat{{\rm{S}}}}_{2{\rm{z}}}-{\vec{\hat{{\rm{S}}}}}_{1}\cdot {\vec{\hat{{\rm{S}}}}}_{2}\right]\)

0

0

Spin-Spin (RF/RF, heteronuclear)

\(\frac{2}{\sqrt{6}}{\hat{{\rm{S}}}}_{1{\rm{z}}}{\hat{{\rm{S}}}}_{2{\rm{z}}}\)

0

0

  1. \({\hat{T}}_{2,n}\) are the rank-2 spherical tensors for spin, whereas \({\hat{S}}_{k,z}\), \({\hat{S}}_{k}^{\pm }=\frac{1}{2}\left({\hat{S}}_{k,x}\pm i{\hat{S}}_{k,y}\right)\) are the spin matrices for single spins.
  2. RF and LF refer to the rotating frame and lab frame, respectively.