Hi,

I tried to read orbitals in from the previously converged calculations, but the energy is much higher than expected.

Below I attached the input (N2/STO-3G).

R = 1.2 angstrom gives E = -107.6772347442

R = 1.22 angstrom gives E = -106.4360604200 (when reading in orbitals from R=1.2)

E = -107.6760114825 (when starting from ROHF orbitals)

I wonder if I am using ref_wfn wrong in the input below. Please let me know if you have some thoughts.

memory 200 Gb

molecule N2 {N

N 1 R

symmetry c1

units angstrom

}

Rvals = [1.20 + i * 0.02 for i in range (241)]

set basis sto-3g

set reference rohf

set soscf true

set DAMPING_PERCENTAGE 50.0

set SOSCF_START_CONVERGENCE 1e-1

set e_convergence 1e-7

set d_convergence 1e-7

set maxiter 10000

set solver_maxiter 100000

set dmrg_irrep 0

set dmrg_multiplicity 1

set restricted_docc [2]

set active [8]

set dmrg_sweep_states [ 500, 500, 1000]

set dmrg_sweep_energy_conv [ 1e-8, 1e-8, 1e-3]

set dmrg_sweep_dvdson_rtol [ 1e-6, 1e-6, 1e-8]

set dmrg_sweep_max_sweeps [ 5, 30, 30]

set dmrg_sweep_noise_prefac [ 0.05, 0.0, 0.0]

set dmrg_print_corr true

set dmrg_mps_write false

set dmrg_unitary_write true

set dmrg_diis true

set dmrg_scf_diis_thr 1e-2

set dmrg_diis_write true

set dmrg_excitation 0 # Ground state

set dmrg_scf_state_avg false

set dmrg_scf_active_space LOC # INPUT; NO; LOC

set dmrg_local_init true

count = 0

N2.R = 1.20

edmrg, prev_dmrg_wfn = energy(“dmrg-scf”, return_wfn=True)

for R in Rvals[1:]:

N2.R = R

set maxiter 10000

set scf guess read

edmrg, cur_dmrg_wfn = energy(“dmrg-scf”, return_wfn=True, ref_wfn=prev_dmrg_wfn)

prev_dmrg_wfn = cur_dmrg_wfn.copy()

count += 1