mirror of
https://github.com/QuantumPackage/qp2.git
synced 2024-09-12 18:58:31 +02:00
51 lines
1.8 KiB
ReStructuredText
51 lines
1.8 KiB
ReStructuredText
======
|
|
casscf
|
|
======
|
|
|
|
|CASSCF| program with the CIPSI algorithm.
|
|
|
|
|
|
Example of inputs for GROUND STATE calculations
|
|
-----------------------------------------------
|
|
NOTICE :: FOR EXCITED STATES CALCULATIONS SEE THE FILE "example_casscf_multistate.sh"
|
|
|
|
a) Small active space : standard CASSCF
|
|
---------------------------------------
|
|
Let's do O2 (triplet) in aug-cc-pvdz with the following geometry (xyz format, Bohr units)
|
|
2
|
|
|
|
O 0.0000000000 0.0000000000 -1.1408000000
|
|
O 0.0000000000 0.0000000000 1.1408000000
|
|
|
|
# Create the ezfio folder
|
|
qp create_ezfio -b aug-cc-pvdz O2.xyz -m 3 -a -o O2_avdz
|
|
|
|
# Start with an ROHF guess
|
|
qp run scf | tee ${EZFIO_FILE}.rohf.out
|
|
|
|
# Get the ROHF energy for check
|
|
qp get hartree_fock energy # should be -149.4684509
|
|
|
|
# Define the full valence active space: the two 1s are doubly occupied, the other 8 valence orbitals are active
|
|
# CASSCF(12e,10orb)
|
|
qp set_mo_class -c "[1-2]" -a "[3-10]" -v "[11-46]"
|
|
|
|
# Specify that you want an near exact CASSCF, i.e. the CIPSI selection will stop at pt2_max = 10^-10
|
|
qp set casscf_cipsi small_active_space True
|
|
# RUN THE CASSCF
|
|
qp run casscf | tee ${EZFIO_FILE}.casscf.out
|
|
# you should find around -149.7243542
|
|
|
|
|
|
b) Large active space : Exploit the selected CI in the active space
|
|
-------------------------------------------------------------------
|
|
#Let us start from the small active space calculation orbitals and add another 10 virtuals: CASSCF(12e,20orb)
|
|
qp set_mo_class -c "[1-2]" -a "[3-20]" -v "[21-46]"
|
|
# As this active space is larger, you unset the small_active_space feature
|
|
qp set casscf_cipsi small_active_space False
|
|
# As it is a large active space, the energy convergence thereshold is set to be 0.0001
|
|
qp run casscf | tee ${EZFIO_FILE}.casscf_large.out
|
|
# you should find around -149.9046
|
|
|
|
|