But we have encountered a new problem. We would like to get the total energy along the IRC direction, but we cannot find the values of the intrinsic reaction coordinate. And through I-Qmol only GEOMETRY vs Energy figure can be observed. Waiting for your reply.And How is the IRC figure obtained?
As mentioned here:
the string is not a rigorous IRC. To determine the latter, use JOBTYPE=RPATH.
Thank you for your help. We calculate the transition state from reactant and product structures and added “JOBTYPE rpath”. The input file command is as follows:
$rem
JOBTYPE fsm
METHOD pbe0
DFT_D = D3_BJ
BASIS aug-cc-pVTZ
FSM_NGRAD 3
FSM_NNODE 18
FSM_MODE 2
FSM_OPT_MODE 2
SYMMETRY false
SYM_IGNORE true
$end
@@@
$molecule
read
$end
$rem
JOBTYPE ts
METHOD pbe0
DFT_D = D3_BJ
BASIS aug-cc-pVTZ
THRESH 14
SCF_ALGORITHM DIIS
SCF_CONVERGENCE 8
SCF_MAX_CYCLES 1000000000
SCF_GUESS read
GEOM_OPT_HESSIAN read
MAX_SCF_CYCLES 250000000
MAX_DIIS_CYCLES=100000000
GEOM_OPT_DMAX 50
GEOM_OPT_MAX_CYCLES 10000000
GEOM_OPT_TOL_DISPLACEMENT=60
GEOM_OPT_TOL_GRADIENT 20
GEOM_OPT_TOL_ENERGY 20
mem_total = 85000
SYMMETRY false
SYM_IGNORE true
$end
@@@
$molecule
read
$end
$rem
JOBTYPE freq
BASIS aug-cc-pVTZ
METHOD pbe0
DFT_D = D3_BJ
SCF_GUESS read
$end
@@@
$molecule
read
$end
$rem
JOBTYPE rpath
BASIS aug-cc-pVTZ
METHOD pbe0
DFT_D = D3_BJ
SCF_GUESS read
RPATH_MAX_CYCLES 250000000
$end
However, where do we look for the correct IRC figure?in .out/Vfile.txt/stringfile.txt/perp_grad_file.txt
At present, i observe the figure by IQMOL is ambiguous and not smooth.Waiting for your reply.
It’s unlikely than anyone can diagnose this problem without the full input file (including coordinates). Furthermore, it is helpful to provide a minimalist example that runs quickly (small molecule and small basis sets). Along those lines, I don’t know why anyone would optimize geometries at PBE0+D3 level using aug-cc-pVTZ basis. Shouldn’t be that sensitive to basis set, 6-31G(d) or 6-31+G(d) is probably just as good and much faster.
