Potential sign error in molecule Hamiltonian

[Qinshu Lyu]

Hello,

There might be a potential sign error for the magnetic matrix of the molecular Hamiltonian.

In XFmolecules.py,  the Zeeman terms in line 177 - 202 are defined according to Brown and Carrington

This convention already includes the minus sign in the Zeeman shift, according to Brown and Carringon (8.179)

However, in the rest part of the pylcp, when including the magnetic shift, a minus sign is added, for example in obe.py:

This causes a sign flip for the Zeeman shift. 

To demonstrate, if using the example code to build CaF hamiltonian:

all the g factors have an opposite sign comparing to literature:

Here is the singleF state as reference:

Thank you,

Qinshu