How To Perform a Calculation

As presently no gradients are available, only single–point calculations are possible:

1. Select in define within the menu cc

   • the wavefunction model (submenu ricc2),

   • frozen core options (submenu freeze),

   • an auxiliary basis for $cbas (submenue cbas),

   • the amount of main memory (option memory),

   and for F12 calculations in addition

   • the F12 options (submenu f12), and

   • a CABS basis (submenu cabs).

   By default a CCSD(F12*) with ansatz 2 and geminal amplitudes fixed by the cusp conditions is performed.¹

        ccsdapprox  ccsd(f12*)
            

   The auxiliary JK basis must be chosen in menu rijk and the exponent for the correlation function must set by editing the $lcg data group of the control file.

2. Do a SCF calculation using either the dscf or the ridft module.

3. Invoke the ccsdf12 program on the command line or with a batch script.