&RASSI NROFjobiph= 2 3 5; 1 2 3; 1 2 3 4 5 NATOrb= 3
6.9.1 RASSI OutputThe RASSI section of the MOLCAS output is basically divided in three parts. Initially, the program prints the information about the JOBIPH files and input file, optionally prints the wave functions, and checks that all the configuration spaces are the same in all the input states. In second place RASSI prints the expectation values of the oneelectron operators, the Hamiltonian matrix, the overlap matrix, and the matrix elements of the oneelectron operators, all for the basis of input RASSCF states. The third part starts with the eigenvectors and eigenvalues for the states computed in the new eigenbasis, as well as the overlap of the computed eigenstates with the input RASSCF states. After that, the expectation values and matrix elements of the oneelectron operators are repeated on the basis of the new energy eigenstates. A final section informs about the occupation numbers of the natural orbitals computed by RASSI, if any. In the Advanced Examples a detailed example of how to interpret the matrix elements output section for the thiophene molecule is displayed. The rest of the output is selfexplanatory. It has to be remembered that to change the default origins for the one electron operators (the dipole moment operator uses the nuclear charge centroid and the higher order operators the center of the nuclear mass) keyword CENTer in GATEWAY must be used. Also, if multipoles higher than order two are required, the option MULTipole has to be used in GATEWAY. The program RASSI can also be used to compute a spinorbit Hamiltonian for the input CASSCF wave functions as defined above. The keyword AMFI has to be used in SEWARD to ensure that the corresponding integrals are available.
&RASSI NROFjobiph= 2 1 1; 1; 1 Spinorbit Ejob The first JOBMIX file contains the wave function for the ground state and the second file the ^{3}B_{2} state discussed above. The keyword Ejob makes the RASSI program use the CASPT2 energies which have been written on the JOBMIX files in the diagonal of the spinorbit Hamiltonian. The output of this calculation will give four spinorbit states and the corresponding transition properties, which can for example be used to compute the radiative lifetime of the triplet state.
6.9.2 RASSI  Basic and Most Common Keywords
CASVB is a program for carrying out quite general types of
nonorthogonal MCSCF calculations, offering, for example, all the advantages
associated with working within a valence bond formalism.

a)  fully variational optimization 
b)  representation of CASSCF wavefunctions using overlap (relatively inexpensive) or energybased criteria. 
CASVB executes the following logical steps: Setup of wavefunction information, starting guess generation, one, or several, optimization steps, various types of analysis of the converged solution.
In the following the main features of the output are outlined, exemplified by the job in the input above. Initially, all relevant information from the previous RASSCF calculation is recovered from the JOBIPH interface file, after which the valence bond wavefunction information is summarized, as shown below. Since spatial configurations have not been specified explicitly in this example, a single covalent configuration is chosen as default. This gives 5 spinadapted VB structures.
Number of active electrons : 6 active orbitals : 6 Total spin : 0.0 State symmetry : 1 Spatial VB configurations  Conf. => Orbitals 1 => 1 2 3 4 5 6 Number of VB configurations : 1 VB structures : 5 VB determinants : 20
The output from the following optimization steps summarizes only the most relevant quantities and convergence information at the default print level. For the last optimization step, for example, The output below thus states that the VB wavefunction was found by maximizing the overlap with a previously optimized CASSCF wavefunction (output by the RASSCF program), and that the spin adaptation was done using the YamanuchiKotani scheme. Convergence was reached in 7 iterations.
 Starting optimization  step 3  Overlapbased optimization (Svb). Optimization algorithm: dFletch Maximum number of iterations: 50 Spin basis: Kotani  Optimization entering local region. Converged ... maximum update to coefficient: 0.59051924E06 Final Svb : 0.9978782695 Number of iterations used: 7
Finally in the output below the converged solution is printed; orbital coefficients (in terms of the active CASSCF MOs) and structure coefficients. The overlap between orbitals are generally of interest, and, as also the structures are nonorthogonal, the structure weights in the total wavefunction. The total VB wavefunction is not symmetryadapted explicitly (although one may ensure the correct symmetry by imposing constraints on orbitals and structure coefficients), so its components in the various irreducible representations can serve to check that it is physically plausible (a well behaved solution generally has just one nonvanishing component).
Next follows the oneelectron density with naturalorbital analysis, again with quantities printed in the basis of the active CASSCF MOs.
Orbital coefficients :  1 2 3 4 5 6 1 0.43397359 0.43397359 0.79451779 0.68987187 0.79451780 0.68987186 2 0.80889967 0.80889967 0.05986171 0.05516284 0.05986171 0.05516284 3 0.00005587 0.00005587 0.20401015 0.20582094 0.20401016 0.20582095 4 0.39667145 0.39667145 0.00000000 0.00000000 0.00000000 0.00000000 5 0.00000001 0.00000001 0.53361427 0.65931951 0.53361425 0.65931952 6 0.00000000 0.00000000 0.19696124 0.20968879 0.19696124 0.20968879 Overlap between orbitals :  1 2 3 4 5 6 1 1.00000000 0.68530352 0.29636622 0.25477647 0.29636623 0.25477647 2 0.68530352 1.00000000 0.29636622 0.25477647 0.29636623 0.25477646 3 0.29636622 0.29636622 1.00000000 0.81994979 0.35292419 0.19890631 4 0.25477647 0.25477647 0.81994979 1.00000000 0.19890634 0.04265679 5 0.29636623 0.29636623 0.35292419 0.19890634 1.00000000 0.81994978 6 0.25477647 0.25477646 0.19890631 0.04265679 0.81994978 1.00000000 Structure coefficients :  0.00000000 0.00000001 0.09455957 0.00000000 0.99551921 Saving VB wavefunction to file VBWFN. Saving VB CI vector to file JOBIPH. Svb : 0.9978782695 Evb : 38.4265149062 ChirgwinCoulson weights of structures :  VB spin+space (norm 1.00000000) : 0.00000000 0.00000000 0.00211737 0.00000000 1.00211737 VB spin only (norm 0.38213666) : 0.00000000 0.00000000 0.00894151 0.00000000 0.99105849 Symmetry contributions to total VB wavefunction :  Irreps 1 to 4 : 0.10000000E+01 0.15118834E17 0.17653074E17 0.49309519E17 Energies for components > 1d10 :  Irreps 1 to 4 : 0.38426515E+02 0.00000000E+00 0.00000000E+00 0.00000000E+00 Oneelectron density :  1 2 3 4 5 6 1 1.98488829 0.00021330 0.00011757 0.00000000 0.00000000 0.00000000 2 0.00021330 1.90209222 0.00006927 0.00000000 0.00000000 0.00000000 3 0.00011757 0.00006927 0.02068155 0.00000000 0.00000000 0.00000000 4 0.00000000 0.00000000 0.00000000 0.09447774 0.00000000 0.00000000 5 0.00000000 0.00000000 0.00000000 0.00000000 1.97572540 0.00030574 6 0.00000000 0.00000000 0.00000000 0.00000000 0.00030574 0.02213479 Natural orbitals :  1 2 3 4 5 6 1 0.99999668 0.00000000 0.00257629 0.00000000 0.00000000 0.00005985 2 0.00257628 0.00000000 0.99999668 0.00000000 0.00000000 0.00003681 3 0.00005995 0.00000000 0.00003666 0.00000000 0.00000001 1.00000000 4 0.00000000 0.00000000 0.00000000 1.00000000 0.00000001 0.00000000 5 0.00000000 0.99999999 0.00000000 0.00000000 0.00015650 0.00000000 6 0.00000000 0.00015650 0.00000000 0.00000001 0.99999999 0.00000001 Occupation numbers :  1 2 3 4 5 6 1 1.98488885 1.97572545 1.90209167 0.09447774 0.02213475 0.02068154