5.8 Examples of autosr

The utility autosr is designed for automatic single reference calculation. Currently supported methods are MP2, CCSD, CCSD(T), DLPNO-CCSD(T), etc (see the full list in Section 4.7.1). Supported basis sets are cc-pVnZ, aug-cc-pVnZ, and the def2- series. The RI technique is turned on by default in MP2 or CC calculations. See the supported programs for MP2_prog and CC_prog in Section 4.7.2.1. By default, HF_prog=Gaussian.

5.8.1 DF-CCSD(T) calculation using Molpro

See an example

%mem=20GB
%nprocshared=4
#p CCSD(T)/cc-pVTZ

mokit{CC_prog=Molpro}

0 1
O   2.72506079   -0.54744525    0.0
H   3.68506079   -0.54744525    0.0
H   2.40460620    0.35749058    0.0

By default, the density fitting (DF, also called RI) technique is turned on and the auxiliary basis set of cc-pVTZ are automatically dealt with, so this is in fact a DF-CCSD(T) calculation. If you do not want to use RI, you can specfidy mokit{CC_prog=Molpro,noRI}.

The T1 diagnostic will be printed if you perform CCSD or CCSD(T) calculations. The Force keyword is supported for calling programs to calculate the analytical nuclear gradients. For example, the CCSD(T) force can be obtained by

#p CCSD(T)/cc-pVTZ

mokit{CC_prog=Molpro,force}

Currently only CC_prog=Molpro or CC_prog=PSI4 is supported for the CCSD(T) force.

5.8.2 DLPNO-CCSD(T1) calculation using ORCA

The input file of autosr is just the Gaussian .gjf file. For example, the DLPNO-CCSD(T1) calculation of a water molecule is shown as follows (h2o.gjf)

%mem=20GB
%nprocshared=4
#p DLPNO-CCSD(T1)/cc-pVTZ

mokit{}

0 1
O   2.72506079   -0.54744525    0.0
H   3.68506079   -0.54744525    0.0
H   2.40460620    0.35749058    0.0

Submit the job

autosr h2o.gjf >h2o.out 2>&1 &

By default, the HF calculation will be performed by calling Gaussian, and the DLPNO-CCSD(T1) calculation will be performed by calling ORCA. The auxiliary basis set of cc-pVTZ are automatically dealt with by autosr. You are supposed to write the memory as large as possible since post-HF jobs usuallty needs a lot of memory. The %maxcore in ORCA input file will be the total memory multiplied by 0.8 and divided by the number of processors.