#!/usr/bin/env qpsh # In this third tutorial, we will compute the ground state and the lowest # singly excited of N2. # 1. Create the EZFIO database, with the def2-svp basis set: qp create_ezfio -b def2-svp n2.zmt # 2. Run the Hartree-Fock calculation: qp run scf | tee scf.out # 3. Set the core MOs as frozen: qp set_frozen_core # 4. Request for two states qp set determinants n_states 2 # 5. Run a CIS qp run cis # 6. Truncate the wave function to the 2 most important determinants : the # Hartree-Fock and one a singly excited determinant (spin symmetry will # be automatically restored in the next calculation) qp edit -n 2 # 7. Set the CIS wave function as the starting trial wave function qp set determinants read_wf True # 8. To avoid collapsing to the ground state and a doubly excited state, # force to use a state-following algorithm qp set davidson state_following True # 9. Terminate when we have 50000 determinants qp set determinants n_det_max 50*10**3 # 10. Run the selected FCI calculation qp run fci | tee fci.out