24 Full-CI calculations

We consider below Full-CI calculations of the X¹A₁ state of the H₂O molecule. In the first instance we consider correlating all electrons. We then perform a valence-only calculation, freezing the O1s orbital through the ACTIVE and CORE directives, specifying a total of 8 electrons on the FULLCI data line.

All-electron Job

          #!/bin/csh -f
          cd /scr1/user
          setenv ed2 h2omain
          setenv ed3 h2odump
          setenv ed6 h2otran
          setenv ftn008 file8
          /scr1/wab/GAMESS-UK/bin/gamess << EOF
          title
          h2o - DZ basis - full-ci
          super off nosym
          zmat angstrom\o\h 1 roh\h 1 roh 2 theta
          variables\roh 0.956 hess 0.7\theta 104.5 hess 0.2 \end
          basis dz
          runtype ci\fullci 14 5 5
          enter 
          EOF

Assuming the above job did not complete in the time allocated, and dumped to disk in a controlled fashion, the following job would act to continue the processing, assuming that the FORTRAN file file8 had been saved, along with the Mainfile, Dumpfile and Transformed integral file.

Restarting the Full-CI job

          #!/bin/csh -f
          cd /scr1/user
          setenv ed2 h2omain
          setenv ed3 h2odump
          setenv ed6 h2otran
          setenv ftn008 file8
          /scr1/wab/GAMESS-UK/bin/gamess << EOF
          restart ci
          title
          h2o - DZ basis - restart full-ci
          super off nosym
          zmat angstrom\o\h 1 roh\h 1 roh 2 theta
          variables\roh 0.956 hess 0.7\theta 104.5 hess 0.2 \end
          basis dz
          runtype ci\fullci 14 5 5
          enter
          EOF

Valence-electron Job

          #!/bin/csh -f
          cd /scr1/user
          setenv ed2 h2omain
          setenv ed3 h2odump
          setenv ftn008 file8
          /scr1/wab/GAMESS-UK/bin/gamess << EOF
          core 8000000
          restart new
          title
          h2o - DZ basis - valence full-ci
          super off nosym
          bypass
          zmat angstrom\o\h 1 roh\h 1 roh 2 theta
          variables\roh 0.956 hess 0.7\theta 104.5 hess 0.2 \end
          basis dz
          runtype ci
          active\2 to 14 end\core\1\end
          fullci 13 4 4
          enter
          EOF

The following points should be noted:

• the use of setenv to allocate the FORTRAN stream ftn008;
• the use of the core pre-directive to specify memory requirements.