Hello,
I’m trying to run CASSCF calculations with nonadiabatic coupling with the following input file.
$molecule
0 3
N 0.0 0.0 0.0
N 0.0 0.0 1.8
$end
$rem
JOBTYPE sp
EXCHANGE hf
BASIS 6-31G*
CAS_METHOD 2 !1 for CAS-CI, 2 for CASSCF
CAS_M_S 0 !M_s value*2
ASCI_DIAG 2 !Arma Sparse=0, Davidson=1, Eigen Sparse=2
CAS_N_ELEC 6 !Number of Active Electrons
CAS_N_ORB 6 !Number of active orbitals
CAS_N_ROOTS 2 !N_roots
THRESH 14
MAX_SCF_CYCLES 400
SCF_CONVERGENCE 6
MEM_TOTAL 4000
MEM_STATIC 1000
SYMMETRY false
SYM_IGNORE true
SCF_ALGORITHM diis
CALC_NAC true
CIS_TRIPLETS true
MAX_CIS_CYCLES 400
CIS_N_ROOTS 2
CIS_DER_NUMSTATE 2
UNRESTRICTED true
$end
$derivative_coupling
comment
1 2
$end
While I’m able to get results running, the problem is that it calculates the excitation energy for 80 excited states, whereas I’m only lloking for the excited energy of 2 states as the value provided in CIS_N_ROOTS.
Does CASSCF support nonadiabatic coupling calculations, as in the documentation I’ve only seen that they can be done in CIS and TDDFT, and if so what settings should I use to have only 2 excited states energies calculated?