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saeed_E

Member

Registered: 2019-12-21

Posts: 157

DLPNO-CCSD(T) TightPNO CBS extrapolation with Orca

Dear Tian,

Please consider the ammonia dimer with an intermolecular HB interaction. Also please suppose we are going to calculate counterpoise-corrected interaction energy (CP-IE) for this dimer using "DLPNO-CCSD(T) TightPNO" with a CBS extrapolation at aug-cc-pVTZ-->aug-cc-pVQZ.
I have prepared the below template taking optimized geometry of dimer. Please, if possible, check it and let me know all is OK or please correct me if you find any mistake particularly about the employed auxiliary basis sets (interestingly, using def2/JK, cc-pVTZ/JK, or aug-cc-pVTZ/JK auxiliary basis sets leads to a quite identical value of CP-IE. Why?). In advance, your kind attention is highly appreciated and please excuse me to get your valuable time.

Sincerely,
Saeed
******************
ORCA TEMPLATE:

! Extrapolate(3/4,aug-cc) TightSCF DLPNO-CCSD(T) RIJK def2/JK TightPNO noautostart miniprint nopop
%maxcore 5000
%pal nprocs  8 end
%id "dimer"
* xyz   0   1
N                 -1.67894600    0.00000500    0.10223900
H                 -2.10781000   -0.81468900   -0.31959700
H                 -0.69331000   -0.00004900   -0.15080600
H                 -2.10772000    0.81472400   -0.31964100
N                  1.56378900    0.00000500   -0.03552900
H                  1.53945200    0.00015800    0.97741300
H                  2.08785700    0.81612100   -0.32728700
H                  2.08763500   -0.81633500   -0.32705800
  *

$new_job
! Extrapolate(3/4,aug-cc) TightSCF DLPNO-CCSD(T) RIJK def2/JK TightPNO noautostart miniprint nopop Pmodel
%maxcore 5000
%pal nprocs  8 end
%id "monomer"
* xyz   0   1
N                 -1.67894600    0.00000500    0.10223900
H                 -2.10781000   -0.81468900   -0.31959700
H                 -0.69331000   -0.00004900   -0.15080600
H                 -2.10772000    0.81472400   -0.31964100
N:                 1.56378900    0.00000500   -0.03552900
H:                 1.53945200    0.00015800    0.97741300
H:                 2.08785700    0.81612100   -0.32728700
H:                 2.08763500   -0.81633500   -0.32705800
  *

$new_job
! Extrapolate(3/4,aug-cc) TightSCF DLPNO-CCSD(T) RIJK def2/JK TightPNO noautostart miniprint nopop Pmodel
%maxcore 5000
%pal nprocs  8 end
%id "monomer"
* xyz   0   1
N:                -1.67894600    0.00000500    0.10223900
H:                -2.10781000   -0.81468900   -0.31959700
H:                -0.69331000   -0.00004900   -0.15080600
H:                -2.10772000    0.81472400   -0.31964100
N                  1.56378900    0.00000500   -0.03552900
H                  1.53945200    0.00015800    0.97741300
H                  2.08785700    0.81612100   -0.32728700
H                  2.08763500   -0.81633500   -0.32705800
  *

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,624

Website

Re: DLPNO-CCSD(T) TightPNO CBS extrapolation with Orca

The system is so small, using DLPNO-CCSD(T) instead of CCSD(T) will not bring significant advantage. Using "RIJK def2/JK" is also deprecated, RIJK will marginally hurt accuracy, and def2/JK is not compatible with aug-cc-pVnZ series of basis set.

I suggest changing keywords simply to
Extrapolate(3/4,aug-cc) TightSCF CCSD(T) noautostart miniprint nopop

saeed_E

Member

Registered: 2019-12-21

Posts: 157

Re: DLPNO-CCSD(T) TightPNO CBS extrapolation with Orca

Dear Tian,
Too many thanks.

Sincerely,
Saeed