You can use command line execution to create and save a Gaussian file based on restricted Hartree-Fock calculations on a 6-31G(d) basis set for water single point energy.

Use your favorite editor to create a file with the following lines and save the file as "spe_hf_6-31g-1.com". Water molecule is described in the form of Z-matrix in the following file.

#T HF/6-31G(d) Pop=Reg Test Water HF Single Point Energy with 6-31G(d) Basis Set 0 1 O H,1,R2 H,1,R3,2,A3 Variables: R2=0.96 R3=0.95990885 A3=109.4731442

Line(s) started with # is used to specify desired calculation type, and other options. T requests terse output from the program (only the essential results). Without T , normal (traditional) Gaussian output is requested. A restricted ( R ) Hartree-Fock ( HF ) calculation using the 6-31G(d) ( 6-31G(D) ) basis set is chosen. Pop=Reg asks to display highest five occupied and lowest five virtual molecular orbitals and other information not included in the output by default. Test will prevent Gaussian from entering this job's results into the site archive. A blank line after the #T line is a one-line description of the calculation. After another blank line, the water molecule is then specified. The first line of the molecule specifications gives the charge and spin multiplicity for the molecule as two free-format integers. For water, the molecule is neutral (charge 0 ) and has spin multiplicity 1 (singlet). Then, the water molecule is represented by Z-matrix format. Notice that there is a blank line at the end of the file.

One can also create a file to describe the water molecule in Cartesian coordinates. Again, use your favorite editor to create a file with the following lines and save the file as "spe_hf_6-31g-2.com".

#T HF/6-31G(d) Pop=Reg Test Water HF Single Point Energy with 6-31G(d) Basis Set 0 1 O -0.464 0.177 0.0 H -0.464 1.137 0.0 H 0.441 -0.143 0.0

Notice that there is again a blank line at the end of the file.

Once the com file is in place. Gaussian can then be run to do the calculation. At the prompt, type the following command to start the calculation. Depending on your setup, use the proper command.

All jobs running on Emerald are to be submitted to the LSF queues. In the following examples, the jobs are submitted to the idle queue on an IBM BladeCenter node on Emerald and 1 processor will be used for each of the jobs. The Gaussian output files will have the filename extension .log in these examples.

At Emerald prompt, type

bsub -q idle -R blade g98 spe_hf_6-31g-1.com spe_hf_6-31g-1.log

for running the Z-matrix file, or type

bsub -q idle -R blade g98 spe_hf_6-31g-2.com spe_hf_6-31g-2.log

for running the Cartesian coordinate file.

The following commands are for csh or tcsh users, if you are using Bourne shell or ksh, you simply replace " >& " with " 2>&1 " for each of the commands.

For csh and tcsh, at the prompt, type

g98 < spe_hf_6-31g-1.com >& spe_hf_6-31g-1.log g98 < spe_hf_6-31g-2.com >& spe_hf_6-31g-2.log

for interactive execution.

If running jobs in the background is preferred, the following commands can be used.

g98 < spe_hf_6-31g-1.com >& spe_hf_6-31g-1.log & g98 < spe_hf_6-31g-2.com >& spe_hf_6-31g-2.log &

If running jobs in the background and logging out of your desktop are preferred, the following commands can be used.

nohup g98 < spe_hf_6-31g-1.com >& spe_hf_6-31g-1.log & nohup g98 < spe_hf_6-31g-2.com >& spe_hf_6-31g-2.log &

If running jobs in the background with lowest priority and logging out of your desktop are preferred, the following commands can be used.

nohup nice +19 g98 < spe_hf_6-31g-1.com >& spe_hf_6-31g-1.log & nohup nice +19 g98 < spe_hf_6-31g-2.com >& spe_hf_6-31g-2.log &

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