Hello,
I am trying to do ASCI+PT2 for atoms, below is the example input, Expected value is -1777.904695 Hartees and I am getting -1777.5863472199. Can anyone take a look at the input below and identify if there is a mistake?
$molecule
0 1
Zn -0.0000000 0.0000000 -0.0000000
$end
$rem
jobtype sp
exchange hf
basis def2-svp
CAS_METHOD 2 !1 for CAS-CI, 2 for CASSCF
CAS_M_S 0 !M_s value*2 (2: triplet)
ASCI_DIAG 2 !Arma Sparse=0, Davidson=1, Eigen Sparse=2
CAS_N_ELEC 12 !N_elec
CAS_N_ORB 9 !N_orb
CAS_N_ROOTS 1 !N_roots
CAS_SOLVER 2 !2=ASCI, 1=Olsen, 0=naive
ASCI_NDETS 28000 !Number of ASCI Determinants
ASCI_SKIP_PT2 0
THRESH 14
max_scf_cycles 400
SCF_CONVERGENCE 8
mem_total 4000
mem_static 1000
ROSCF true
symmetry false
sym_ignore true
scf_algorithm diis_gdm
$end
Did you obtain the reference value from a previously run Q-Chem output? Could you please provide the versions of your current and reference Q-Chem installations? Was the same input used for the two calculations?
Dear Kaushik the reference value I have taken from SI of https://pubs.acs.org/doi/10.1021/acs.jctc.9b00674. and I am using Q-Chem 6.0.2. Input is not the same, I am a beginner at Qchem and this method.
Unfortunately, we do not have access to this publication, so you will have to give more information about the reference calculations. For example, are the REM settings “CAS_METHOD = 2”, “CAS_N_ELEC = 12”, and “CAS_N_ORB = 9” consistent with the reference? The ROHF energy seems to be consistent with the reported value.
The reference paper doesn’t talk about active space, I have tried full valence and many other options but couldn’t crack it. ROHF is the same.
Then, I suggest that you contact one of the publication authors directly as it will be quicker than playing with different CAS settings. I recommend that you either let Q-Chem Support (support@q-chem.com) know or post here if there is any discrepancy following that.
