=================== Quickstart tutorial =================== If you are already familiar with multiplet calculations this page and our :ref:`examples page ` are a good part to start. Otherwise, checkout our :ref:`Pedagogical examples ` to learn the concepts behind how edrixs works. Use edrixs as an ED calculator ------------------------------ edrixs can be used as a simple ED calculator to get eigenvalues (eigenvectors) of a many-body Hamiltonian with small size dimension (:math:`< 1,000`). We will give an example to get eigenvalues for a :math:`t_{2g}`-orbital system (:math:`l_{eff}=1`). There are 6 orbitals including spin. Launch your favorite python terminal:: >>> import edrixs >>> import scipy >>> norb = 6 >>> noccu = 2 >>> Ud, JH = edrixs.UJ_to_UdJH(4, 1) >>> F0, F2, F4 = edrixs.UdJH_to_F0F2F4(Ud, JH) >>> umat = edrixs.get_umat_slater('t2g', F0, F2, F4) >>> emat = edrixs.atom_hsoc('t2g', 0.2) >>> basis = edrixs.get_fock_bin_by_N(norb, noccu) >>> H = edrixs.build_opers(4, umat, basis) >>> e1, v1 = scipy.linalg.eigh(H) >>> H += edrixs.build_opers(2, emat, basis) >>> e2, v2 = scipy.linalg.eigh(H) >>> print(e1) [1. 1. 1. 1. 1. 1. 1. 1. 1. 3. 3. 3. 3. 3. 6.] >>> print(e2) [0.890519 0.890519 0.890519 0.890519 0.890519 1.1 1.1 1.1 1.183391 3.009481 3.009481 3.009481 3.009481 3.009481 6.016609] Hello RIXS! ----------- This is a "Hello World!" example for RIXS simulations at Ni (:math:`3d^8`) :math:`L_{2/3}` edges. :math:`L_3` means transition from Ni-:math:`2p_{3/2}` to Ni-:math:`3d`, and :math:`L_2` means transition from Ni-:math:`2p_{1/2}` to Ni-:math:`3d`. .. plot:: pyplots/helloworld.py :include-source: