qp-demo/examples/3_n2/run.qpsh

#!/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