From qiskit_nature.drivers.second_quantization import gaussianforcesdriver # if you ran gaussian elsewhere and already have the output file driver = gaussianforcesdriver(logfile=./co2_freq_b3lyp_631g.log) By using the option freq=savenm, the frequency information will be saved in the checkpoint file anisole_s0.chk Driver = gaussianforcesdriver(logfile=co2_freq_b3lyp_631g.log) # define a harmonic basis with two modals per mode from qiskit_nature.second_q.problems import harmonicbasis
Maezzy Angelo (@maezzyyangelo) on Threads
Driver = gaussianforcesdriver(logfile=co2_freq_b3lyp_631g.log) step 3
Defining the vibrational basis i defined the harmonic basis functions, specifying the number of energy levels (modals) for each vibrational mode
For co₂, which has four primary vibrational modes, i started with two modals per mode for simplicity. Sparsepauliop(['iiiiiiii', 'iiiiiiiz', 'iiiiiizi', 'iiiiizii', 'iiiixxii', 'iiiiyyii', 'iiiiziii', 'iiiziiii', 'iiziiiii', 'iziiiiii', 'ziiiiiii', 'iiiiiziz. Gaussian calculates the single point energy of each intermediate geometry it generates during optimization as well as at the start of a vibrational frequency analysis We can exploit this fact to save us from having to set up another calculation
To find the single point energy search eqmecyhex.log for the last occurrence of scf done: These keywords will start a gaussian job which first optimizes the geometry for the initial state and then calculates the frequencies of the optimized geometry
